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Diffstat (limited to 'mfbt/tests/gtest/TestSpan.cpp')
| -rw-r--r-- | mfbt/tests/gtest/TestSpan.cpp | 2355 |
1 files changed, 2355 insertions, 0 deletions
diff --git a/mfbt/tests/gtest/TestSpan.cpp b/mfbt/tests/gtest/TestSpan.cpp new file mode 100644 index 0000000000..fb7db0d158 --- /dev/null +++ b/mfbt/tests/gtest/TestSpan.cpp @@ -0,0 +1,2355 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +// Adapted from +// https://github.com/Microsoft/GSL/blob/3819df6e378ffccf0e29465afe99c3b324c2aa70/tests/Span_tests.cpp + +#include "gtest/gtest.h" + +#include "mozilla/Array.h" +#include "mozilla/Span.h" + +#include "nsString.h" +#include "nsTArray.h" +#include "mozilla/Range.h" + +#include <type_traits> + +#define SPAN_TEST(name) TEST(SpanTest, name) +#define CHECK_THROW(a, b) + +using namespace mozilla; + +static_assert(std::is_convertible_v<Range<int>, Span<const int>>, + "Range should convert into const"); +static_assert(std::is_convertible_v<Range<const int>, Span<const int>>, + "const Range should convert into const"); +static_assert(!std::is_convertible_v<Range<const int>, Span<int>>, + "Range should not drop const in conversion"); +static_assert(std::is_convertible_v<Span<int>, Range<const int>>, + "Span should convert into const"); +static_assert(std::is_convertible_v<Span<const int>, Range<const int>>, + "const Span should convert into const"); +static_assert(!std::is_convertible_v<Span<const int>, Range<int>>, + "Span should not drop const in conversion"); +static_assert(std::is_convertible_v<Span<const int>, Span<const int>>, + "const Span should convert into const"); +static_assert(std::is_convertible_v<Span<int>, Span<const int>>, + "Span should convert into const"); +static_assert(!std::is_convertible_v<Span<const int>, Span<int>>, + "Span should not drop const in conversion"); +static_assert(std::is_convertible_v<const nsTArray<int>, Span<const int>>, + "const nsTArray should convert into const"); +static_assert(std::is_convertible_v<nsTArray<int>, Span<const int>>, + "nsTArray should convert into const"); +static_assert(!std::is_convertible_v<const nsTArray<int>, Span<int>>, + "nsTArray should not drop const in conversion"); +static_assert(std::is_convertible_v<nsTArray<const int>, Span<const int>>, + "nsTArray should convert into const"); +static_assert(!std::is_convertible_v<nsTArray<const int>, Span<int>>, + "nsTArray should not drop const in conversion"); + +static_assert(std::is_convertible_v<const std::vector<int>, Span<const int>>, + "const std::vector should convert into const"); +static_assert(std::is_convertible_v<std::vector<int>, Span<const int>>, + "std::vector should convert into const"); +static_assert(!std::is_convertible_v<const std::vector<int>, Span<int>>, + "std::vector should not drop const in conversion"); + +/** + * Rust slice-compatible nullptr replacement value. + */ +#define SLICE_CONST_INT_PTR reinterpret_cast<const int*>(alignof(const int)) + +/** + * Rust slice-compatible nullptr replacement value. + */ +#define SLICE_INT_PTR reinterpret_cast<int*>(alignof(int)) + +/** + * Rust slice-compatible nullptr replacement value. + */ +#define SLICE_CONST_INT_PTR_PTR \ + reinterpret_cast<const int**>(alignof(const int*)) + +/** + * Rust slice-compatible nullptr replacement value. + */ +#define SLICE_INT_PTR_PTR reinterpret_cast<int**>(alignof(int*)) + +namespace { +struct BaseClass {}; +struct DerivedClass : BaseClass {}; +} // namespace + +void AssertSpanOfThreeInts(Span<const int> s) { + ASSERT_EQ(s.size(), 3U); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + ASSERT_EQ(s[2], 3); +} + +void AssertSpanOfThreeChars(Span<const char> s) { + ASSERT_EQ(s.size(), 3U); + ASSERT_EQ(s[0], 'a'); + ASSERT_EQ(s[1], 'b'); + ASSERT_EQ(s[2], 'c'); +} + +void AssertSpanOfThreeChar16s(Span<const char16_t> s) { + ASSERT_EQ(s.size(), 3U); + ASSERT_EQ(s[0], 'a'); + ASSERT_EQ(s[1], 'b'); + ASSERT_EQ(s[2], 'c'); +} + +void AssertSpanOfThreeCharsViaString(const nsACString& aStr) { + AssertSpanOfThreeChars(aStr); +} + +void AssertSpanOfThreeChar16sViaString(const nsAString& aStr) { + AssertSpanOfThreeChar16s(aStr); +} + +SPAN_TEST(default_constructor) { + { + Span<int> s; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int> cs; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { + Span<int, 0> s; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int, 0> cs; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + Span<int, 1> s; + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); // explains why it can't compile +#endif + } + + { + Span<int> s{}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int> cs{}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } +} + +SPAN_TEST(size_optimization) { + { + Span<int> s; + ASSERT_EQ(sizeof(s), sizeof(int*) + sizeof(size_t)); + } + + { + Span<int, 0> s; + ASSERT_EQ(sizeof(s), sizeof(int*)); + } +} + +SPAN_TEST(from_nullptr_constructor) { + { + Span<int> s = nullptr; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int> cs = nullptr; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { + Span<int, 0> s = nullptr; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int, 0> cs = nullptr; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + Span<int, 1> s = nullptr; + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); // explains why it can't compile +#endif + } + + { + Span<int> s{nullptr}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int> cs{nullptr}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { + Span<int*> s{nullptr}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR_PTR); + + Span<const int*> cs{nullptr}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR_PTR); + } +} + +SPAN_TEST(from_nullptr_length_constructor) { + { + Span<int> s{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int> cs{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + + { + Span<int, 0> s{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + + Span<const int, 0> cs{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR); + } + +#if 0 + { + auto workaround_macro = []() { Span<int, 1> s{ nullptr, static_cast<Span<int>::index_type>(0) }; }; + CHECK_THROW(workaround_macro(), fail_fast); + } + + { + auto workaround_macro = []() { Span<int> s{nullptr, 1}; }; + CHECK_THROW(workaround_macro(), fail_fast); + + auto const_workaround_macro = []() { Span<const int> cs{nullptr, 1}; }; + CHECK_THROW(const_workaround_macro(), fail_fast); + } + + { + auto workaround_macro = []() { Span<int, 0> s{nullptr, 1}; }; + CHECK_THROW(workaround_macro(), fail_fast); + + auto const_workaround_macro = []() { Span<const int, 0> s{nullptr, 1}; }; + CHECK_THROW(const_workaround_macro(), fail_fast); + } +#endif + { + Span<int*> s{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR_PTR); + + Span<const int*> cs{nullptr, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(cs.Length(), 0U); + ASSERT_EQ(cs.data(), SLICE_CONST_INT_PTR_PTR); + } +} + +SPAN_TEST(from_pointer_length_constructor) { + int arr[4] = {1, 2, 3, 4}; + + { + Span<int> s{&arr[0], 2}; + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + Span<int, 2> s{&arr[0], 2}; + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + int* p = nullptr; + Span<int> s{p, static_cast<Span<int>::index_type>(0)}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + } + +#if 0 + { + int* p = nullptr; + auto workaround_macro = [=]() { Span<int> s{p, 2}; }; + CHECK_THROW(workaround_macro(), fail_fast); + } +#endif + + { + auto s = Span(&arr[0], 2); + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + int* p = nullptr; + auto s = Span(p, static_cast<Span<int>::index_type>(0)); + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + } + +#if 0 + { + int* p = nullptr; + auto workaround_macro = [=]() { Span(p, 2); }; + CHECK_THROW(workaround_macro(), fail_fast); + } +#endif +} + +SPAN_TEST(from_pointer_pointer_constructor) { + int arr[4] = {1, 2, 3, 4}; + + { + Span<int> s{&arr[0], &arr[2]}; + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + Span<int, 2> s{&arr[0], &arr[2]}; + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + Span<int> s{&arr[0], &arr[0]}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<int, 0> s{&arr[0], &arr[0]}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + // this will fail the std::distance() precondition, which asserts on MSVC + // debug builds + //{ + // auto workaround_macro = [&]() { Span<int> s{&arr[1], &arr[0]}; }; + // CHECK_THROW(workaround_macro(), fail_fast); + //} + + // this will fail the std::distance() precondition, which asserts on MSVC + // debug builds + //{ + // int* p = nullptr; + // auto workaround_macro = [&]() { Span<int> s{&arr[0], p}; }; + // CHECK_THROW(workaround_macro(), fail_fast); + //} + + { + int* p = nullptr; + Span<int> s{p, p}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + } + + { + int* p = nullptr; + Span<int, 0> s{p, p}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + } + + // this will fail the std::distance() precondition, which asserts on MSVC + // debug builds + //{ + // int* p = nullptr; + // auto workaround_macro = [&]() { Span<int> s{&arr[0], p}; }; + // CHECK_THROW(workaround_macro(), fail_fast); + //} + + { + auto s = Span(&arr[0], &arr[2]); + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[1], 2); + } + + { + auto s = Span(&arr[0], &arr[0]); + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + int* p = nullptr; + auto s = Span(p, p); + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), SLICE_INT_PTR); + } +} + +SPAN_TEST(from_array_constructor) { + int arr[5] = {1, 2, 3, 4, 5}; + + { + Span<int> s{arr}; + ASSERT_EQ(s.Length(), 5U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<int, 5> s{arr}; + ASSERT_EQ(s.Length(), 5U); + ASSERT_EQ(s.data(), &arr[0]); + } + + int arr2d[2][3] = {{1, 2, 3}, {4, 5, 6}}; + +#ifdef CONFIRM_COMPILATION_ERRORS + { Span<int, 6> s{arr}; } + + { + Span<int, 0> s{arr}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<int> s{arr2d}; + ASSERT_EQ(s.Length(), 6U); + ASSERT_EQ(s.data(), &arr2d[0][0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[5], 6); + } + + { + Span<int, 0> s{arr2d}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr2d[0][0]); + } + + { Span<int, 6> s{arr2d}; } +#endif + { + Span<int[3]> s{&(arr2d[0]), 1}; + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), &arr2d[0]); + } + + int arr3d[2][3][2] = {{{1, 2}, {3, 4}, {5, 6}}, {{7, 8}, {9, 10}, {11, 12}}}; + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<int> s{arr3d}; + ASSERT_EQ(s.Length(), 12U); + ASSERT_EQ(s.data(), &arr3d[0][0][0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[11], 12); + } + + { + Span<int, 0> s{arr3d}; + ASSERT_EQ(s.Length(), 0U); + ASSERT_EQ(s.data(), &arr3d[0][0][0]); + } + + { Span<int, 11> s{arr3d}; } + + { + Span<int, 12> s{arr3d}; + ASSERT_EQ(s.Length(), 12U); + ASSERT_EQ(s.data(), &arr3d[0][0][0]); + ASSERT_EQ(s[0], 1); + ASSERT_EQ(s[5], 6); + } +#endif + { + Span<int[3][2]> s{&arr3d[0], 1}; + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), &arr3d[0]); + } + + { + auto s = Span(arr); + ASSERT_EQ(s.Length(), 5U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + auto s = Span(&(arr2d[0]), 1); + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), &arr2d[0]); + } + + { + auto s = Span(&arr3d[0], 1); + ASSERT_EQ(s.Length(), 1U); + ASSERT_EQ(s.data(), &arr3d[0]); + } +} + +SPAN_TEST(from_dynamic_array_constructor) { + double(*arr)[3][4] = new double[100][3][4]; + + { + Span<double> s(&arr[0][0][0], 10); + ASSERT_EQ(s.Length(), 10U); + ASSERT_EQ(s.data(), &arr[0][0][0]); + } + + { + auto s = Span(&arr[0][0][0], 10); + ASSERT_EQ(s.Length(), 10U); + ASSERT_EQ(s.data(), &arr[0][0][0]); + } + + delete[] arr; +} + +SPAN_TEST(from_std_array_constructor) { + std::array<int, 4> arr = {{1, 2, 3, 4}}; + + { + Span<int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + + Span<const int> cs{arr}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(cs.data(), arr.data()); + } + + { + Span<int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + + Span<const int, 4> cs{arr}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(cs.data(), arr.data()); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), arr.data()); + + Span<const int, 2> cs{arr}; + ASSERT_EQ(cs.size(), 2U); + ASSERT_EQ(cs.data(), arr.data()); + } + + { + Span<int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), arr.data()); + + Span<const int, 0> cs{arr}; + ASSERT_EQ(cs.size(), 0U); + ASSERT_EQ(cs.data(), arr.data()); + } + + { Span<int, 5> s{arr}; } + + { + auto get_an_array = []() -> std::array<int, 4> { return {1, 2, 3, 4}; }; + auto take_a_Span = [](Span<int> s) { static_cast<void>(s); }; + // try to take a temporary std::array + take_a_Span(get_an_array()); + } +#endif + + { + auto get_an_array = []() -> std::array<int, 4> { return {{1, 2, 3, 4}}; }; + auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); }; + // try to take a temporary std::array + take_a_Span(get_an_array()); + } + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } +} + +SPAN_TEST(from_const_std_array_constructor) { + const std::array<int, 4> arr = {{1, 2, 3, 4}}; + + { + Span<const int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } + + { + Span<const int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<const int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), arr.data()); + } + + { + Span<const int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), arr.data()); + } + + { Span<const int, 5> s{arr}; } +#endif + + { + auto get_an_array = []() -> const std::array<int, 4> { + return {{1, 2, 3, 4}}; + }; + auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); }; + // try to take a temporary std::array + take_a_Span(get_an_array()); + } + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } +} + +SPAN_TEST(from_std_array_const_constructor) { + std::array<const int, 4> arr = {{1, 2, 3, 4}}; + + { + Span<const int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } + + { + Span<const int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<const int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), arr.data()); + } + + { + Span<const int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), arr.data()); + } + + { Span<const int, 5> s{arr}; } + + { Span<int, 4> s{arr}; } +#endif + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size())); + ASSERT_EQ(s.data(), arr.data()); + } +} + +SPAN_TEST(from_mozilla_array_constructor) { + mozilla::Array<int, 4> arr(1, 2, 3, 4); + + { + Span<int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + + Span<const int> cs{arr}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(cs.data(), &arr[0]); + } + + { + Span<int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + + Span<const int, 4> cs{arr}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(cs.data(), &arr[0]); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + + Span<const int, 2> cs{arr}; + ASSERT_EQ(cs.size(), 2U); + ASSERT_EQ(cs.data(), &arr[0]); + } + + { + Span<int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + + Span<const int, 0> cs{arr}; + ASSERT_EQ(cs.size(), 0U); + ASSERT_EQ(cs.data(), &arr[0]); + } + + { Span<int, 5> s{arr}; } + + { + auto get_an_array = []() -> mozilla::Array<int, 4> { return {1, 2, 3, 4}; }; + auto take_a_Span = [](Span<int> s) { static_cast<void>(s); }; + // try to take a temporary mozilla::Array + take_a_Span(get_an_array()); + } +#endif + + { + auto get_an_array = []() -> mozilla::Array<int, 4> { return {1, 2, 3, 4}; }; + auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); }; + // try to take a temporary mozilla::Array + take_a_Span(get_an_array()); + } + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } +} + +SPAN_TEST(from_const_mozilla_array_constructor) { + const mozilla::Array<int, 4> arr(1, 2, 3, 4); + + { + Span<const int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<const int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<const int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<const int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { Span<const int, 5> s{arr}; } +#endif + +#if 0 + { + auto get_an_array = []() -> const mozilla::Array<int, 4> { + return { 1, 2, 3, 4 }; + }; + auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); }; + // try to take a temporary mozilla::Array + take_a_Span(get_an_array()); + } +#endif + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } +} + +SPAN_TEST(from_mozilla_array_const_constructor) { + mozilla::Array<const int, 4> arr(1, 2, 3, 4); + + { + Span<const int> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<const int, 4> s{arr}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + Span<const int, 2> s{arr}; + ASSERT_EQ(s.size(), 2U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { + Span<const int, 0> s{arr}; + ASSERT_EQ(s.size(), 0U); + ASSERT_EQ(s.data(), &arr[0]); + } + + { Span<const int, 5> s{arr}; } + + { Span<int, 4> s{arr}; } +#endif + + { + auto s = Span(arr); + ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin())); + ASSERT_EQ(s.data(), &arr[0]); + } +} + +SPAN_TEST(from_container_constructor) { + std::vector<int> v = {1, 2, 3}; + const std::vector<int> cv = v; + + { + AssertSpanOfThreeInts(v); + + Span<int> s{v}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.size())); + ASSERT_EQ(s.data(), v.data()); + + Span<const int> cs{v}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.size())); + ASSERT_EQ(cs.data(), v.data()); + } + + std::string str = "hello"; + const std::string cstr = "hello"; + + { +#ifdef CONFIRM_COMPILATION_ERRORS + Span<char> s{str}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(str.size())); + ASSERT_EQ(s.data(), str.data()); +#endif + Span<const char> cs{str}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.size())); + ASSERT_EQ(cs.data(), str.data()); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + Span<char> s{cstr}; +#endif + Span<const char> cs{cstr}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(cstr.size())); + ASSERT_EQ(cs.data(), cstr.data()); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + auto get_temp_vector = []() -> std::vector<int> { return {}; }; + auto use_Span = [](Span<int> s) { static_cast<void>(s); }; + use_Span(get_temp_vector()); +#endif + } + + { + auto get_temp_vector = []() -> std::vector<int> { return {}; }; + auto use_Span = [](Span<const int> s) { static_cast<void>(s); }; + use_Span(get_temp_vector()); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + auto get_temp_string = []() -> std::string { return {}; }; + auto use_Span = [](Span<char> s) { static_cast<void>(s); }; + use_Span(get_temp_string()); +#endif + } + + { + auto get_temp_string = []() -> std::string { return {}; }; + auto use_Span = [](Span<const char> s) { static_cast<void>(s); }; + use_Span(get_temp_string()); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + auto get_temp_vector = []() -> const std::vector<int> { return {}; }; + auto use_Span = [](Span<const char> s) { static_cast<void>(s); }; + use_Span(get_temp_vector()); +#endif + } + + { + auto get_temp_string = []() -> const std::string { return {}; }; + auto use_Span = [](Span<const char> s) { static_cast<void>(s); }; + use_Span(get_temp_string()); + } + + { +#ifdef CONFIRM_COMPILATION_ERRORS + std::map<int, int> m; + Span<int> s{m}; +#endif + } + + { + auto s = Span(v); + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.size())); + ASSERT_EQ(s.data(), v.data()); + + auto cs = Span(cv); + ASSERT_EQ(cs.size(), narrow_cast<size_t>(cv.size())); + ASSERT_EQ(cs.data(), cv.data()); + } +} + +SPAN_TEST(from_xpcom_collections) { + { + nsTArray<int> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + AssertSpanOfThreeInts(v); + + Span<int> s{v}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + + Span<const int> cs{v}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(cs.data(), v.Elements()); + ASSERT_EQ(cs[2], 3); + } + { + nsTArray<int> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + AssertSpanOfThreeInts(v); + + auto s = Span(v); + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + } + { + AutoTArray<int, 5> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + AssertSpanOfThreeInts(v); + + Span<int> s{v}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + + Span<const int> cs{v}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(cs.data(), v.Elements()); + ASSERT_EQ(cs[2], 3); + } + { + AutoTArray<int, 5> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + AssertSpanOfThreeInts(v); + + auto s = Span(v); + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + } + { + FallibleTArray<int> v; + *(v.AppendElement(fallible)) = 1; + *(v.AppendElement(fallible)) = 2; + *(v.AppendElement(fallible)) = 3; + + AssertSpanOfThreeInts(v); + + Span<int> s{v}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + + Span<const int> cs{v}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(cs.data(), v.Elements()); + ASSERT_EQ(cs[2], 3); + } + { + FallibleTArray<int> v; + *(v.AppendElement(fallible)) = 1; + *(v.AppendElement(fallible)) = 2; + *(v.AppendElement(fallible)) = 3; + + AssertSpanOfThreeInts(v); + + auto s = Span(v); + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + } + { + nsAutoString str; + str.AssignLiteral(u"abc"); + + AssertSpanOfThreeChar16s(str); + AssertSpanOfThreeChar16sViaString(str); + + Span<char16_t> s{str.GetMutableData()}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length())); + ASSERT_EQ(s.data(), str.BeginWriting()); + ASSERT_EQ(s[2], 'c'); + + Span<const char16_t> cs{str}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.Length())); + ASSERT_EQ(cs.data(), str.BeginReading()); + ASSERT_EQ(cs[2], 'c'); + } + { + nsAutoString str; + str.AssignLiteral(u"abc"); + + AssertSpanOfThreeChar16s(str); + AssertSpanOfThreeChar16sViaString(str); + + auto s = Span(str); + ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length())); + ASSERT_EQ(s.data(), str.BeginReading()); + ASSERT_EQ(s[2], 'c'); + } + { + nsAutoCString str; + str.AssignLiteral("abc"); + + AssertSpanOfThreeChars(str); + AssertSpanOfThreeCharsViaString(str); + + Span<const uint8_t> cs{str}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.Length())); + ASSERT_EQ(cs.data(), reinterpret_cast<const uint8_t*>(str.BeginReading())); + ASSERT_EQ(cs[2], 'c'); + } + { + nsAutoCString str; + str.AssignLiteral("abc"); + + AssertSpanOfThreeChars(str); + AssertSpanOfThreeCharsViaString(str); + + auto s = Span(str); + ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length())); + ASSERT_EQ(s.data(), str.BeginReading()); + ASSERT_EQ(s[2], 'c'); + } + { + nsTArray<int> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + Range<int> r(v.Elements(), v.Length()); + + AssertSpanOfThreeInts(r); + + Span<int> s{r}; + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + + Span<const int> cs{r}; + ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(cs.data(), v.Elements()); + ASSERT_EQ(cs[2], 3); + } + { + nsTArray<int> v; + v.AppendElement(1); + v.AppendElement(2); + v.AppendElement(3); + + Range<int> r(v.Elements(), v.Length()); + + AssertSpanOfThreeInts(r); + + auto s = Span(r); + ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length())); + ASSERT_EQ(s.data(), v.Elements()); + ASSERT_EQ(s[2], 3); + } +} + +SPAN_TEST(from_cstring) { + { + const char* str = nullptr; + auto cs = MakeStringSpan(str); + ASSERT_EQ(cs.size(), 0U); + } + { + const char* str = "abc"; + + auto cs = MakeStringSpan(str); + ASSERT_EQ(cs.size(), 3U); + ASSERT_EQ(cs.data(), str); + ASSERT_EQ(cs[2], 'c'); + + static_assert(MakeStringSpan("abc").size() == 3U); + static_assert(MakeStringSpan("abc")[2] == 'c'); + +#ifdef CONFIRM_COMPILATION_ERRORS + Span<const char> scccl("literal"); // error + + Span<const char> sccel; + sccel = "literal"; // error + + cs = Span("literal"); // error +#endif + } + { + char arr[4] = {'a', 'b', 'c', 0}; + + auto cs = MakeStringSpan(arr); + ASSERT_EQ(cs.size(), 3U); + ASSERT_EQ(cs.data(), arr); + ASSERT_EQ(cs[2], 'c'); + + cs = Span(arr); + ASSERT_EQ(cs.size(), 4U); // zero terminator is part of the array span. + ASSERT_EQ(cs.data(), arr); + ASSERT_EQ(cs[2], 'c'); + ASSERT_EQ(cs[3], '\0'); // zero terminator is part of the array span. + +#ifdef CONFIRM_COMPILATION_ERRORS + Span<char> scca(arr); // error + Span<const char> sccca(arr); // error + + Span<const char> scccea; + scccea = arr; // error +#endif + } + { + const char16_t* str = nullptr; + auto cs = MakeStringSpan(str); + ASSERT_EQ(cs.size(), 0U); + } + { + char16_t arr[4] = {'a', 'b', 'c', 0}; + const char16_t* str = arr; + + auto cs = MakeStringSpan(str); + ASSERT_EQ(cs.size(), 3U); + ASSERT_EQ(cs.data(), str); + ASSERT_EQ(cs[2], 'c'); + + static_assert(MakeStringSpan(u"abc").size() == 3U); + static_assert(MakeStringSpan(u"abc")[2] == u'c'); + + cs = MakeStringSpan(arr); + ASSERT_EQ(cs.size(), 3U); + ASSERT_EQ(cs.data(), str); + ASSERT_EQ(cs[2], 'c'); + + cs = Span(arr); + ASSERT_EQ(cs.size(), 4U); // zero terminator is part of the array span. + ASSERT_EQ(cs.data(), str); + ASSERT_EQ(cs[2], 'c'); + ASSERT_EQ(cs[3], '\0'); // zero terminator is part of the array span. + +#ifdef CONFIRM_COMPILATION_ERRORS + Span<char16_t> scca(arr); // error + + Span<const char16_t> scccea; + scccea = arr; // error + + Span<const char16_t> scccl(u"literal"); // error + + Span<const char16_t>* sccel; + *sccel = u"literal"; // error + + cs = Span(u"literal"); // error +#endif + } +} + +SPAN_TEST(from_convertible_Span_constructor){{Span<DerivedClass> avd; +Span<const DerivedClass> avcd = avd; +static_cast<void>(avcd); +} + +{ +#ifdef CONFIRM_COMPILATION_ERRORS + Span<DerivedClass> avd; + Span<BaseClass> avb = avd; + static_cast<void>(avb); +#endif +} + +#ifdef CONFIRM_COMPILATION_ERRORS +{ + Span<int> s; + Span<unsigned int> s2 = s; + static_cast<void>(s2); +} + +{ + Span<int> s; + Span<const unsigned int> s2 = s; + static_cast<void>(s2); +} + +{ + Span<int> s; + Span<short> s2 = s; + static_cast<void>(s2); +} +#endif +} + +SPAN_TEST(copy_move_and_assignment) { + Span<int> s1; + ASSERT_TRUE(s1.empty()); + + int arr[] = {3, 4, 5}; + + Span<const int> s2 = arr; + ASSERT_EQ(s2.Length(), 3U); + ASSERT_EQ(s2.data(), &arr[0]); + + s2 = s1; + ASSERT_TRUE(s2.empty()); + + auto get_temp_Span = [&]() -> Span<int> { return {&arr[1], 2}; }; + auto use_Span = [&](Span<const int> s) { + ASSERT_EQ(s.Length(), 2U); + ASSERT_EQ(s.data(), &arr[1]); + }; + use_Span(get_temp_Span()); + + s1 = get_temp_Span(); + ASSERT_EQ(s1.Length(), 2U); + ASSERT_EQ(s1.data(), &arr[1]); +} + +SPAN_TEST(first) { + int arr[5] = {1, 2, 3, 4, 5}; + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.First<2>().Length(), 2U); + ASSERT_EQ(av.First(2).Length(), 2U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.First<0>().Length(), 0U); + ASSERT_EQ(av.First(0).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.First<5>().Length(), 5U); + ASSERT_EQ(av.First(5).Length(), 5U); + } + +#if 0 + { + Span<int, 5> av = arr; +# ifdef CONFIRM_COMPILATION_ERRORS + ASSERT_EQ(av.First<6>().Length() , 6U); + ASSERT_EQ(av.First<-1>().Length() , -1); +# endif + CHECK_THROW(av.First(6).Length(), fail_fast); + } +#endif + + { + Span<int> av; + ASSERT_EQ(av.First<0>().Length(), 0U); + ASSERT_EQ(av.First(0).Length(), 0U); + } +} + +SPAN_TEST(last) { + int arr[5] = {1, 2, 3, 4, 5}; + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.Last<2>().Length(), 2U); + ASSERT_EQ(av.Last(2).Length(), 2U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.Last<0>().Length(), 0U); + ASSERT_EQ(av.Last(0).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.Last<5>().Length(), 5U); + ASSERT_EQ(av.Last(5).Length(), 5U); + } + +#if 0 + { + Span<int, 5> av = arr; +# ifdef CONFIRM_COMPILATION_ERRORS + ASSERT_EQ(av.Last<6>().Length() , 6U); +# endif + CHECK_THROW(av.Last(6).Length(), fail_fast); + } +#endif + + { + Span<int> av; + ASSERT_EQ(av.Last<0>().Length(), 0U); + ASSERT_EQ(av.Last(0).Length(), 0U); + } +} + +SPAN_TEST(from_to) { + int arr[5] = {1, 2, 3, 4, 5}; + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.From(3).Length(), 2U); + ASSERT_EQ(av.From(2)[1], 4); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.From(5).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.From(0).Length(), 5U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.To(3).Length(), 3U); + ASSERT_EQ(av.To(3)[1], 2); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.To(0).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.To(5).Length(), 5U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.FromTo(1, 4).Length(), 3U); + ASSERT_EQ(av.FromTo(1, 4)[1], 3); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.FromTo(2, 2).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.FromTo(0, 5).Length(), 5U); + } +} + +SPAN_TEST(Subspan) { + int arr[5] = {1, 2, 3, 4, 5}; + + { + Span<int, 5> av = arr; + ASSERT_EQ((av.Subspan<2, 2>().Length()), 2U); + ASSERT_EQ(av.Subspan(2, 2).Length(), 2U); + ASSERT_EQ(av.Subspan(2, 3).Length(), 3U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ((av.Subspan<0, 0>().Length()), 0U); + ASSERT_EQ(av.Subspan(0, 0).Length(), 0U); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ((av.Subspan<0, 5>().Length()), 5U); + ASSERT_EQ(av.Subspan(0, 5).Length(), 5U); + CHECK_THROW(av.Subspan(0, 6).Length(), fail_fast); + CHECK_THROW(av.Subspan(1, 5).Length(), fail_fast); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ((av.Subspan<4, 0>().Length()), 0U); + ASSERT_EQ(av.Subspan(4, 0).Length(), 0U); + ASSERT_EQ(av.Subspan(5, 0).Length(), 0U); + CHECK_THROW(av.Subspan(6, 0).Length(), fail_fast); + } + + { + Span<int> av; + ASSERT_EQ((av.Subspan<0, 0>().Length()), 0U); + ASSERT_EQ(av.Subspan(0, 0).Length(), 0U); + CHECK_THROW((av.Subspan<1, 0>().Length()), fail_fast); + } + + { + Span<int> av; + ASSERT_EQ(av.Subspan(0).Length(), 0U); + CHECK_THROW(av.Subspan(1).Length(), fail_fast); + } + + { + Span<int> av = arr; + ASSERT_EQ(av.Subspan(0).Length(), 5U); + ASSERT_EQ(av.Subspan(1).Length(), 4U); + ASSERT_EQ(av.Subspan(4).Length(), 1U); + ASSERT_EQ(av.Subspan(5).Length(), 0U); + CHECK_THROW(av.Subspan(6).Length(), fail_fast); + auto av2 = av.Subspan(1); + for (int i = 0; i < 4; ++i) ASSERT_EQ(av2[i], i + 2); + } + + { + Span<int, 5> av = arr; + ASSERT_EQ(av.Subspan(0).Length(), 5U); + ASSERT_EQ(av.Subspan(1).Length(), 4U); + ASSERT_EQ(av.Subspan(4).Length(), 1U); + ASSERT_EQ(av.Subspan(5).Length(), 0U); + CHECK_THROW(av.Subspan(6).Length(), fail_fast); + auto av2 = av.Subspan(1); + for (int i = 0; i < 4; ++i) ASSERT_EQ(av2[i], i + 2); + } +} + +SPAN_TEST(at_call) { + int arr[4] = {1, 2, 3, 4}; + + { + Span<int> s = arr; + ASSERT_EQ(s.at(0), 1); + CHECK_THROW(s.at(5), fail_fast); + } + + { + int arr2d[2] = {1, 6}; + Span<int, 2> s = arr2d; + ASSERT_EQ(s.at(0), 1); + ASSERT_EQ(s.at(1), 6); + CHECK_THROW(s.at(2), fail_fast); + } +} + +SPAN_TEST(operator_function_call) { + int arr[4] = {1, 2, 3, 4}; + + { + Span<int> s = arr; + ASSERT_EQ(s(0), 1); + CHECK_THROW(s(5), fail_fast); + } + + { + int arr2d[2] = {1, 6}; + Span<int, 2> s = arr2d; + ASSERT_EQ(s(0), 1); + ASSERT_EQ(s(1), 6); + CHECK_THROW(s(2), fail_fast); + } +} + +SPAN_TEST(iterator_default_init) { + Span<int>::iterator it1; + Span<int>::iterator it2; + ASSERT_EQ(it1, it2); +} + +SPAN_TEST(const_iterator_default_init) { + Span<int>::const_iterator it1; + Span<int>::const_iterator it2; + ASSERT_EQ(it1, it2); +} + +SPAN_TEST(iterator_conversions) { + Span<int>::iterator badIt; + Span<int>::const_iterator badConstIt; + ASSERT_EQ(badIt, badConstIt); + + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + auto it = s.begin(); + auto cit = s.cbegin(); + + ASSERT_EQ(it, cit); + ASSERT_EQ(cit, it); + + Span<int>::const_iterator cit2 = it; + ASSERT_EQ(cit2, cit); + + Span<int>::const_iterator cit3 = it + 4; + ASSERT_EQ(cit3, s.cend()); +} + +SPAN_TEST(iterator_comparisons) { + int a[] = {1, 2, 3, 4}; + { + Span<int> s = a; + Span<int>::iterator it = s.begin(); + auto it2 = it + 1; + Span<int>::const_iterator cit = s.cbegin(); + + ASSERT_EQ(it, cit); + ASSERT_EQ(cit, it); + ASSERT_EQ(it, it); + ASSERT_EQ(cit, cit); + ASSERT_EQ(cit, s.begin()); + ASSERT_EQ(s.begin(), cit); + ASSERT_EQ(s.cbegin(), cit); + ASSERT_EQ(it, s.begin()); + ASSERT_EQ(s.begin(), it); + + ASSERT_NE(it, it2); + ASSERT_NE(it2, it); + ASSERT_NE(it, s.end()); + ASSERT_NE(it2, s.end()); + ASSERT_NE(s.end(), it); + ASSERT_NE(it2, cit); + ASSERT_NE(cit, it2); + + ASSERT_LT(it, it2); + ASSERT_LE(it, it2); + ASSERT_LE(it2, s.end()); + ASSERT_LT(it, s.end()); + ASSERT_LE(it, cit); + ASSERT_LE(cit, it); + ASSERT_LT(cit, it2); + ASSERT_LE(cit, it2); + ASSERT_LT(cit, s.end()); + ASSERT_LE(cit, s.end()); + + ASSERT_GT(it2, it); + ASSERT_GE(it2, it); + ASSERT_GT(s.end(), it2); + ASSERT_GE(s.end(), it2); + ASSERT_GT(it2, cit); + ASSERT_GE(it2, cit); + } +} + +SPAN_TEST(begin_end) { + { + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + Span<int>::iterator it = s.begin(); + Span<int>::iterator it2 = std::begin(s); + ASSERT_EQ(it, it2); + + it = s.end(); + it2 = std::end(s); + ASSERT_EQ(it, it2); + } + + { + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + auto it = s.begin(); + auto first = it; + ASSERT_EQ(it, first); + ASSERT_EQ(*it, 1); + + auto beyond = s.end(); + ASSERT_NE(it, beyond); + CHECK_THROW(*beyond, fail_fast); + + ASSERT_EQ(beyond - first, 4); + ASSERT_EQ(first - first, 0); + ASSERT_EQ(beyond - beyond, 0); + + ++it; + ASSERT_EQ(it - first, 1); + ASSERT_EQ(*it, 2); + *it = 22; + ASSERT_EQ(*it, 22); + ASSERT_EQ(beyond - it, 3); + + it = first; + ASSERT_EQ(it, first); + while (it != s.end()) { + *it = 5; + ++it; + } + + ASSERT_EQ(it, beyond); + ASSERT_EQ(it - beyond, 0); + + for (auto& n : s) { + ASSERT_EQ(n, 5); + } + } +} + +SPAN_TEST(cbegin_cend) { +#if 0 + { + int a[] = { 1, 2, 3, 4 }; + Span<int> s = a; + + Span<int>::const_iterator cit = s.cbegin(); + Span<int>::const_iterator cit2 = std::cbegin(s); + ASSERT_EQ(cit , cit2); + + cit = s.cend(); + cit2 = std::cend(s); + ASSERT_EQ(cit , cit2); + } +#endif + { + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + auto it = s.cbegin(); + auto first = it; + ASSERT_EQ(it, first); + ASSERT_EQ(*it, 1); + + auto beyond = s.cend(); + ASSERT_NE(it, beyond); + CHECK_THROW(*beyond, fail_fast); + + ASSERT_EQ(beyond - first, 4); + ASSERT_EQ(first - first, 0); + ASSERT_EQ(beyond - beyond, 0); + + ++it; + ASSERT_EQ(it - first, 1); + ASSERT_EQ(*it, 2); + ASSERT_EQ(beyond - it, 3); + + int last = 0; + it = first; + ASSERT_EQ(it, first); + while (it != s.cend()) { + ASSERT_EQ(*it, last + 1); + + last = *it; + ++it; + } + + ASSERT_EQ(it, beyond); + ASSERT_EQ(it - beyond, 0); + } +} + +SPAN_TEST(rbegin_rend) { + { + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + auto it = s.rbegin(); + auto first = it; + ASSERT_EQ(it, first); + ASSERT_EQ(*it, 4); + + auto beyond = s.rend(); + ASSERT_NE(it, beyond); + CHECK_THROW(*beyond, fail_fast); + + ASSERT_EQ(beyond - first, 4); + ASSERT_EQ(first - first, 0); + ASSERT_EQ(beyond - beyond, 0); + + ++it; + ASSERT_EQ(it - first, 1); + ASSERT_EQ(*it, 3); + *it = 22; + ASSERT_EQ(*it, 22); + ASSERT_EQ(beyond - it, 3); + + it = first; + ASSERT_EQ(it, first); + while (it != s.rend()) { + *it = 5; + ++it; + } + + ASSERT_EQ(it, beyond); + ASSERT_EQ(it - beyond, 0); + + for (auto& n : s) { + ASSERT_EQ(n, 5); + } + } +} + +SPAN_TEST(crbegin_crend) { + { + int a[] = {1, 2, 3, 4}; + Span<int> s = a; + + auto it = s.crbegin(); + auto first = it; + ASSERT_EQ(it, first); + ASSERT_EQ(*it, 4); + + auto beyond = s.crend(); + ASSERT_NE(it, beyond); + CHECK_THROW(*beyond, fail_fast); + + ASSERT_EQ(beyond - first, 4); + ASSERT_EQ(first - first, 0); + ASSERT_EQ(beyond - beyond, 0); + + ++it; + ASSERT_EQ(it - first, 1); + ASSERT_EQ(*it, 3); + ASSERT_EQ(beyond - it, 3); + + it = first; + ASSERT_EQ(it, first); + int last = 5; + while (it != s.crend()) { + ASSERT_EQ(*it, last - 1); + last = *it; + + ++it; + } + + ASSERT_EQ(it, beyond); + ASSERT_EQ(it - beyond, 0); + } +} + +SPAN_TEST(comparison_operators) { + { + Span<int> s1 = nullptr; + Span<int> s2 = nullptr; + ASSERT_EQ(s1, s2); + ASSERT_FALSE(s1 != s2); + ASSERT_FALSE(s1 < s2); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s1, s2); + ASSERT_EQ(s2, s1); + ASSERT_FALSE(s2 != s1); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s2, s1); + ASSERT_FALSE(s2 > s1); + ASSERT_GE(s2, s1); + } + + { + int arr[] = {2, 1}; + Span<int> s1 = arr; + Span<int> s2 = arr; + + ASSERT_EQ(s1, s2); + ASSERT_FALSE(s1 != s2); + ASSERT_FALSE(s1 < s2); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s1, s2); + ASSERT_EQ(s2, s1); + ASSERT_FALSE(s2 != s1); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s2, s1); + ASSERT_FALSE(s2 > s1); + ASSERT_GE(s2, s1); + } + + { + int arr[] = {2, 1}; // bigger + + Span<int> s1 = nullptr; + Span<int> s2 = arr; + + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_LT(s1, s2); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s2 <= s1); + ASSERT_GT(s2, s1); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s2, s1); + ASSERT_FALSE(s1 >= s2); + } + + { + int arr1[] = {1, 2}; + int arr2[] = {1, 2}; + Span<int> s1 = arr1; + Span<int> s2 = arr2; + + ASSERT_EQ(s1, s2); + ASSERT_FALSE(s1 != s2); + ASSERT_FALSE(s1 < s2); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s1, s2); + ASSERT_EQ(s2, s1); + ASSERT_FALSE(s2 != s1); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s2, s1); + ASSERT_FALSE(s2 > s1); + ASSERT_GE(s2, s1); + } + + { + int arr[] = {1, 2, 3}; + + AssertSpanOfThreeInts(arr); + + Span<int> s1 = {&arr[0], 2}; // shorter + Span<int> s2 = arr; // longer + + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_LT(s1, s2); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s2 <= s1); + ASSERT_GT(s2, s1); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s2, s1); + ASSERT_FALSE(s1 >= s2); + } + + { + int arr1[] = {1, 2}; // smaller + int arr2[] = {2, 1}; // bigger + + Span<int> s1 = arr1; + Span<int> s2 = arr2; + + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_NE(s1, s2); + ASSERT_NE(s2, s1); + ASSERT_LT(s1, s2); + ASSERT_FALSE(s2 < s1); + ASSERT_LE(s1, s2); + ASSERT_FALSE(s2 <= s1); + ASSERT_GT(s2, s1); + ASSERT_FALSE(s1 > s2); + ASSERT_GE(s2, s1); + ASSERT_FALSE(s1 >= s2); + } +} + +SPAN_TEST(as_bytes) { + int a[] = {1, 2, 3, 4}; + + { + Span<const int> s = a; + ASSERT_EQ(s.Length(), 4U); + Span<const uint8_t> bs = AsBytes(s); + ASSERT_EQ(static_cast<const void*>(bs.data()), + static_cast<const void*>(s.data())); + ASSERT_EQ(bs.Length(), s.LengthBytes()); + } + + { + Span<int> s; + auto bs = AsBytes(s); + ASSERT_EQ(bs.Length(), s.Length()); + ASSERT_EQ(bs.Length(), 0U); + ASSERT_EQ(bs.size_bytes(), 0U); + ASSERT_EQ(static_cast<const void*>(bs.data()), + static_cast<const void*>(s.data())); + ASSERT_EQ(bs.data(), reinterpret_cast<const uint8_t*>(SLICE_INT_PTR)); + } + + { + Span<int> s = a; + auto bs = AsBytes(s); + ASSERT_EQ(static_cast<const void*>(bs.data()), + static_cast<const void*>(s.data())); + ASSERT_EQ(bs.Length(), s.LengthBytes()); + } +} + +SPAN_TEST(as_writable_bytes) { + int a[] = {1, 2, 3, 4}; + + { +#ifdef CONFIRM_COMPILATION_ERRORS + // you should not be able to get writeable bytes for const objects + Span<const int> s = a; + ASSERT_EQ(s.Length(), 4U); + Span<const byte> bs = AsWritableBytes(s); + ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data())); + ASSERT_EQ(bs.Length(), s.LengthBytes()); +#endif + } + + { + Span<int> s; + auto bs = AsWritableBytes(s); + ASSERT_EQ(bs.Length(), s.Length()); + ASSERT_EQ(bs.Length(), 0U); + ASSERT_EQ(bs.size_bytes(), 0U); + ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data())); + ASSERT_EQ(bs.data(), reinterpret_cast<uint8_t*>(SLICE_INT_PTR)); + } + + { + Span<int> s = a; + auto bs = AsWritableBytes(s); + ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data())); + ASSERT_EQ(bs.Length(), s.LengthBytes()); + } +} + +SPAN_TEST(as_chars) { + const uint8_t a[] = {1, 2, 3, 4}; + Span<const uint8_t> u = Span(a); + Span<const char> c = AsChars(u); + ASSERT_EQ(static_cast<const void*>(u.data()), + static_cast<const void*>(c.data())); + ASSERT_EQ(u.size(), c.size()); +} + +SPAN_TEST(as_writable_chars) { + uint8_t a[] = {1, 2, 3, 4}; + Span<uint8_t> u = Span(a); + Span<char> c = AsWritableChars(u); + ASSERT_EQ(static_cast<void*>(u.data()), static_cast<void*>(c.data())); + ASSERT_EQ(u.size(), c.size()); +} + +SPAN_TEST(fixed_size_conversions) { + int arr[] = {1, 2, 3, 4}; + + // converting to an Span from an equal size array is ok + Span<int, 4> s4 = arr; + ASSERT_EQ(s4.Length(), 4U); + + // converting to dynamic_range is always ok + { + Span<int> s = s4; + ASSERT_EQ(s.Length(), s4.Length()); + static_cast<void>(s); + } + +// initialization or assignment to static Span that REDUCES size is NOT ok +#ifdef CONFIRM_COMPILATION_ERRORS + { Span<int, 2> s = arr; } + { + Span<int, 2> s2 = s4; + static_cast<void>(s2); + } +#endif + +#if 0 + // even when done dynamically + { + Span<int> s = arr; + auto f = [&]() { + Span<int, 2> s2 = s; + static_cast<void>(s2); + }; + CHECK_THROW(f(), fail_fast); + } +#endif + + // but doing so explicitly is ok + + // you can convert statically + { + Span<int, 2> s2 = {arr, 2}; + static_cast<void>(s2); + } + { + Span<int, 1> s1 = s4.First<1>(); + static_cast<void>(s1); + } + + // ...or dynamically + { + // NB: implicit conversion to Span<int,1> from Span<int> + Span<int, 1> s1 = s4.First(1); + static_cast<void>(s1); + } + +#if 0 + // initialization or assignment to static Span that requires size INCREASE is not ok. + int arr2[2] = {1, 2}; +#endif + +#ifdef CONFIRM_COMPILATION_ERRORS + { Span<int, 4> s3 = arr2; } + { + Span<int, 2> s2 = arr2; + Span<int, 4> s4a = s2; + } +#endif + +#if 0 + { + auto f = [&]() { + Span<int, 4> _s4 = {arr2, 2}; + static_cast<void>(_s4); + }; + CHECK_THROW(f(), fail_fast); + } + + // this should fail - we are trying to assign a small dynamic Span to a fixed_size larger one + Span<int> av = arr2; + auto f = [&]() { + Span<int, 4> _s4 = av; + static_cast<void>(_s4); + }; + CHECK_THROW(f(), fail_fast); +#endif +} + +#if 0 + SPAN_TEST(interop_with_std_regex) + { + char lat[] = { '1', '2', '3', '4', '5', '6', 'E', 'F', 'G' }; + Span<char> s = lat; + auto f_it = s.begin() + 7; + + std::match_results<Span<char>::iterator> match; + + std::regex_match(s.begin(), s.end(), match, std::regex(".*")); + ASSERT_EQ(match.ready()); + ASSERT_TRUE(!match.empty()); + ASSERT_TRUE(match[0].matched); + ASSERT_TRUE(match[0].first , s.begin()); + ASSERT_EQ(match[0].second , s.end()); + + std::regex_search(s.begin(), s.end(), match, std::regex("F")); + ASSERT_TRUE(match.ready()); + ASSERT_TRUE(!match.empty()); + ASSERT_TRUE(match[0].matched); + ASSERT_EQ(match[0].first , f_it); + ASSERT_EQ(match[0].second , (f_it + 1)); + } + +SPAN_TEST(interop_with_gsl_at) +{ + int arr[5] = { 1, 2, 3, 4, 5 }; + Span<int> s{ arr }; + ASSERT_EQ(at(s, 0) , 1 ); +ASSERT_EQ(at(s, 1) , 2U); +} +#endif + +SPAN_TEST(default_constructible) { + ASSERT_TRUE((std::is_default_constructible<Span<int>>::value)); + ASSERT_TRUE((std::is_default_constructible<Span<int, 0>>::value)); + ASSERT_TRUE((!std::is_default_constructible<Span<int, 42>>::value)); +} + +SPAN_TEST(type_inference) { + static constexpr int arr[5] = {1, 2, 3, 4, 5}; + constexpr auto s = Span{arr}; + static_assert(std::is_same_v<const Span<const int, 5>, decltype(s)>); + static_assert(arr == s.Elements()); +} + +SPAN_TEST(split_at_dynamic_with_dynamic_extent) { + static constexpr int arr[5] = {1, 2, 3, 4, 5}; + constexpr Span<const int> s = Span{arr}; + + { // Split at begin. + constexpr auto splitAt0Result = s.SplitAt(0); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt0Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt0Result.second)>); + ASSERT_EQ(s.Elements(), splitAt0Result.second.Elements()); + ASSERT_EQ(0u, splitAt0Result.first.Length()); + ASSERT_EQ(5u, splitAt0Result.second.Length()); + } + + { // Split at end. + constexpr auto splitAt5Result = s.SplitAt(s.Length()); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt5Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt5Result.second)>); + ASSERT_EQ(s.Elements(), splitAt5Result.first.Elements()); + ASSERT_EQ(5u, splitAt5Result.first.Length()); + ASSERT_EQ(0u, splitAt5Result.second.Length()); + } + + { + // Split inside. + constexpr auto splitAt3Result = s.SplitAt(3); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt3Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt3Result.second)>); + ASSERT_EQ(s.Elements(), splitAt3Result.first.Elements()); + ASSERT_EQ(s.Elements() + 3, splitAt3Result.second.Elements()); + ASSERT_EQ(3u, splitAt3Result.first.Length()); + ASSERT_EQ(2u, splitAt3Result.second.Length()); + } +} + +SPAN_TEST(split_at_dynamic_with_static_extent) { + static constexpr int arr[5] = {1, 2, 3, 4, 5}; + constexpr auto s = Span{arr}; + + { + // Split at begin. + constexpr auto splitAt0Result = s.SplitAt(0); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt0Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt0Result.second)>); + ASSERT_EQ(s.Elements(), splitAt0Result.second.Elements()); + } + + { + // Split at end. + constexpr auto splitAt5Result = s.SplitAt(s.Length()); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt5Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt5Result.second)>); + ASSERT_EQ(s.Elements(), splitAt5Result.first.Elements()); + } + + { + // Split inside. + constexpr auto splitAt3Result = s.SplitAt(3); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt3Result.first)>); + static_assert( + std::is_same_v<Span<const int>, decltype(splitAt3Result.second)>); + ASSERT_EQ(s.Elements(), splitAt3Result.first.Elements()); + ASSERT_EQ(s.Elements() + 3, splitAt3Result.second.Elements()); + } +} + +SPAN_TEST(split_at_static) { + static constexpr int arr[5] = {1, 2, 3, 4, 5}; + constexpr auto s = Span{arr}; + + // Split at begin. + constexpr auto splitAt0Result = s.SplitAt<0>(); + static_assert( + std::is_same_v<Span<const int, 0>, decltype(splitAt0Result.first)>); + static_assert( + std::is_same_v<Span<const int, 5>, decltype(splitAt0Result.second)>); + static_assert(splitAt0Result.second.Elements() == s.Elements()); + + // Split at end. + constexpr auto splitAt5Result = s.SplitAt<s.Length()>(); + static_assert(std::is_same_v<Span<const int, s.Length()>, + decltype(splitAt5Result.first)>); + static_assert( + std::is_same_v<Span<const int, 0>, decltype(splitAt5Result.second)>); + static_assert(splitAt5Result.first.Elements() == s.Elements()); + + // Split inside. + constexpr auto splitAt3Result = s.SplitAt<3>(); + static_assert( + std::is_same_v<Span<const int, 3>, decltype(splitAt3Result.first)>); + static_assert( + std::is_same_v<Span<const int, 2>, decltype(splitAt3Result.second)>); + static_assert(splitAt3Result.first.Elements() == s.Elements()); + static_assert(splitAt3Result.second.Elements() == s.Elements() + 3); +} + +SPAN_TEST(as_const_dynamic) { + static int arr[5] = {1, 2, 3, 4, 5}; + auto span = Span{arr, 5}; + auto constSpan = span.AsConst(); + static_assert(std::is_same_v<Span<const int>, decltype(constSpan)>); +} + +SPAN_TEST(as_const_static) { + { + static constexpr int constArr[5] = {1, 2, 3, 4, 5}; + constexpr auto span = Span{constArr}; // is already a Span<const int> + constexpr auto constSpan = span.AsConst(); + + static_assert( + std::is_same_v<const Span<const int, 5>, decltype(constSpan)>); + } + + { + static int arr[5] = {1, 2, 3, 4, 5}; + auto span = Span{arr}; + auto constSpan = span.AsConst(); + static_assert(std::is_same_v<Span<const int, 5>, decltype(constSpan)>); + } +} + +SPAN_TEST(construct_from_iterators_dynamic) { + const int constArr[5] = {1, 2, 3, 4, 5}; + auto constSpan = Span{constArr}; + + // const from const + { + const auto wholeSpan = Span{constSpan.cbegin(), constSpan.cend()}; + static_assert(std::is_same_v<decltype(wholeSpan), const Span<const int>>); + ASSERT_TRUE(constSpan == wholeSpan); + + const auto emptyBeginSpan = Span{constSpan.cbegin(), constSpan.cbegin()}; + ASSERT_TRUE(emptyBeginSpan.IsEmpty()); + + const auto emptyEndSpan = Span{constSpan.cend(), constSpan.cend()}; + ASSERT_TRUE(emptyEndSpan.IsEmpty()); + + const auto subSpan = Span{constSpan.cbegin() + 1, constSpan.cend() - 1}; + ASSERT_EQ(constSpan.Length() - 2, subSpan.Length()); + ASSERT_EQ(constSpan.Elements() + 1, subSpan.Elements()); + } + + int arr[5] = {1, 2, 3, 4, 5}; + auto span = Span{arr}; + + // const from non-const + { + const auto wholeSpan = Span{span.cbegin(), span.cend()}; + static_assert(std::is_same_v<decltype(wholeSpan), const Span<const int>>); + // XXX Can't use span == wholeSpan because of difference in constness. + ASSERT_EQ(span.Elements(), wholeSpan.Elements()); + ASSERT_EQ(span.Length(), wholeSpan.Length()); + + const auto emptyBeginSpan = Span{span.cbegin(), span.cbegin()}; + ASSERT_TRUE(emptyBeginSpan.IsEmpty()); + + const auto emptyEndSpan = Span{span.cend(), span.cend()}; + ASSERT_TRUE(emptyEndSpan.IsEmpty()); + + const auto subSpan = Span{span.cbegin() + 1, span.cend() - 1}; + ASSERT_EQ(span.Length() - 2, subSpan.Length()); + ASSERT_EQ(span.Elements() + 1, subSpan.Elements()); + } + + // non-const from non-const + { + const auto wholeSpan = Span{span.begin(), span.end()}; + static_assert(std::is_same_v<decltype(wholeSpan), const Span<int>>); + ASSERT_TRUE(span == wholeSpan); + + const auto emptyBeginSpan = Span{span.begin(), span.begin()}; + ASSERT_TRUE(emptyBeginSpan.IsEmpty()); + + const auto emptyEndSpan = Span{span.end(), span.end()}; + ASSERT_TRUE(emptyEndSpan.IsEmpty()); + + const auto subSpan = Span{span.begin() + 1, span.end() - 1}; + ASSERT_EQ(span.Length() - 2, subSpan.Length()); + } +} + +SPAN_TEST(construct_from_iterators_static) { + static constexpr int arr[5] = {1, 2, 3, 4, 5}; + constexpr auto constSpan = Span{arr}; + + // const + { + const auto wholeSpan = Span{constSpan.cbegin(), constSpan.cend()}; + static_assert(std::is_same_v<decltype(wholeSpan), const Span<const int>>); + ASSERT_TRUE(constSpan == wholeSpan); + + const auto emptyBeginSpan = Span{constSpan.cbegin(), constSpan.cbegin()}; + ASSERT_TRUE(emptyBeginSpan.IsEmpty()); + + const auto emptyEndSpan = Span{constSpan.cend(), constSpan.cend()}; + ASSERT_TRUE(emptyEndSpan.IsEmpty()); + + const auto subSpan = Span{constSpan.cbegin() + 1, constSpan.cend() - 1}; + ASSERT_EQ(constSpan.Length() - 2, subSpan.Length()); + ASSERT_EQ(constSpan.Elements() + 1, subSpan.Elements()); + } +} + +SPAN_TEST(construct_from_container_with_type_deduction) { + std::vector<int> vec = {1, 2, 3, 4, 5}; + + // from const + { + const auto& constVecRef = vec; + + auto span = Span{constVecRef}; + static_assert(std::is_same_v<decltype(span), Span<const int>>); + } + + // from non-const + { + auto span = Span{vec}; + static_assert(std::is_same_v<decltype(span), Span<int>>); + } +} |