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Diffstat (limited to 'src/fmtlib/fmt/compile.h')
-rw-r--r-- | src/fmtlib/fmt/compile.h | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/src/fmtlib/fmt/compile.h b/src/fmtlib/fmt/compile.h new file mode 100644 index 0000000..94e13c0 --- /dev/null +++ b/src/fmtlib/fmt/compile.h @@ -0,0 +1,607 @@ +// Formatting library for C++ - experimental format string compilation +// +// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors +// All rights reserved. +// +// For the license information refer to format.h. + +#ifndef FMT_COMPILE_H_ +#define FMT_COMPILE_H_ + +#include "format.h" + +FMT_BEGIN_NAMESPACE +namespace detail { + +template <typename Char, typename InputIt> +FMT_CONSTEXPR inline counting_iterator copy_str(InputIt begin, InputIt end, + counting_iterator it) { + return it + (end - begin); +} + +template <typename OutputIt> class truncating_iterator_base { + protected: + OutputIt out_; + size_t limit_; + size_t count_ = 0; + + truncating_iterator_base() : out_(), limit_(0) {} + + truncating_iterator_base(OutputIt out, size_t limit) + : out_(out), limit_(limit) {} + + public: + using iterator_category = std::output_iterator_tag; + using value_type = typename std::iterator_traits<OutputIt>::value_type; + using difference_type = std::ptrdiff_t; + using pointer = void; + using reference = void; + FMT_UNCHECKED_ITERATOR(truncating_iterator_base); + + OutputIt base() const { return out_; } + size_t count() const { return count_; } +}; + +// An output iterator that truncates the output and counts the number of objects +// written to it. +template <typename OutputIt, + typename Enable = typename std::is_void< + typename std::iterator_traits<OutputIt>::value_type>::type> +class truncating_iterator; + +template <typename OutputIt> +class truncating_iterator<OutputIt, std::false_type> + : public truncating_iterator_base<OutputIt> { + mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_; + + public: + using value_type = typename truncating_iterator_base<OutputIt>::value_type; + + truncating_iterator() = default; + + truncating_iterator(OutputIt out, size_t limit) + : truncating_iterator_base<OutputIt>(out, limit) {} + + truncating_iterator& operator++() { + if (this->count_++ < this->limit_) ++this->out_; + return *this; + } + + truncating_iterator operator++(int) { + auto it = *this; + ++*this; + return it; + } + + value_type& operator*() const { + return this->count_ < this->limit_ ? *this->out_ : blackhole_; + } +}; + +template <typename OutputIt> +class truncating_iterator<OutputIt, std::true_type> + : public truncating_iterator_base<OutputIt> { + public: + truncating_iterator() = default; + + truncating_iterator(OutputIt out, size_t limit) + : truncating_iterator_base<OutputIt>(out, limit) {} + + template <typename T> truncating_iterator& operator=(T val) { + if (this->count_++ < this->limit_) *this->out_++ = val; + return *this; + } + + truncating_iterator& operator++() { return *this; } + truncating_iterator& operator++(int) { return *this; } + truncating_iterator& operator*() { return *this; } +}; + +// A compile-time string which is compiled into fast formatting code. +class compiled_string {}; + +template <typename S> +struct is_compiled_string : std::is_base_of<compiled_string, S> {}; + +/** + \rst + Converts a string literal *s* into a format string that will be parsed at + compile time and converted into efficient formatting code. Requires C++17 + ``constexpr if`` compiler support. + + **Example**:: + + // Converts 42 into std::string using the most efficient method and no + // runtime format string processing. + std::string s = fmt::format(FMT_COMPILE("{}"), 42); + \endrst + */ +#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction) +# define FMT_COMPILE(s) \ + FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit) +#else +# define FMT_COMPILE(s) FMT_STRING(s) +#endif + +#if FMT_USE_NONTYPE_TEMPLATE_ARGS +template <typename Char, size_t N, + fmt::detail_exported::fixed_string<Char, N> Str> +struct udl_compiled_string : compiled_string { + using char_type = Char; + explicit constexpr operator basic_string_view<char_type>() const { + return {Str.data, N - 1}; + } +}; +#endif + +template <typename T, typename... Tail> +const T& first(const T& value, const Tail&...) { + return value; +} + +#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction) +template <typename... Args> struct type_list {}; + +// Returns a reference to the argument at index N from [first, rest...]. +template <int N, typename T, typename... Args> +constexpr const auto& get([[maybe_unused]] const T& first, + [[maybe_unused]] const Args&... rest) { + static_assert(N < 1 + sizeof...(Args), "index is out of bounds"); + if constexpr (N == 0) + return first; + else + return detail::get<N - 1>(rest...); +} + +template <typename Char, typename... Args> +constexpr int get_arg_index_by_name(basic_string_view<Char> name, + type_list<Args...>) { + return get_arg_index_by_name<Args...>(name); +} + +template <int N, typename> struct get_type_impl; + +template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> { + using type = + remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>; +}; + +template <int N, typename T> +using get_type = typename get_type_impl<N, T>::type; + +template <typename T> struct is_compiled_format : std::false_type {}; + +template <typename Char> struct text { + basic_string_view<Char> data; + using char_type = Char; + + template <typename OutputIt, typename... Args> + constexpr OutputIt format(OutputIt out, const Args&...) const { + return write<Char>(out, data); + } +}; + +template <typename Char> +struct is_compiled_format<text<Char>> : std::true_type {}; + +template <typename Char> +constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos, + size_t size) { + return {{&s[pos], size}}; +} + +template <typename Char> struct code_unit { + Char value; + using char_type = Char; + + template <typename OutputIt, typename... Args> + constexpr OutputIt format(OutputIt out, const Args&...) const { + return write<Char>(out, value); + } +}; + +// This ensures that the argument type is convertible to `const T&`. +template <typename T, int N, typename... Args> +constexpr const T& get_arg_checked(const Args&... args) { + const auto& arg = detail::get<N>(args...); + if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) { + return arg.value; + } else { + return arg; + } +} + +template <typename Char> +struct is_compiled_format<code_unit<Char>> : std::true_type {}; + +// A replacement field that refers to argument N. +template <typename Char, typename T, int N> struct field { + using char_type = Char; + + template <typename OutputIt, typename... Args> + constexpr OutputIt format(OutputIt out, const Args&... args) const { + return write<Char>(out, get_arg_checked<T, N>(args...)); + } +}; + +template <typename Char, typename T, int N> +struct is_compiled_format<field<Char, T, N>> : std::true_type {}; + +// A replacement field that refers to argument with name. +template <typename Char> struct runtime_named_field { + using char_type = Char; + basic_string_view<Char> name; + + template <typename OutputIt, typename T> + constexpr static bool try_format_argument( + OutputIt& out, + // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9 + [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) { + if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) { + if (arg_name == arg.name) { + out = write<Char>(out, arg.value); + return true; + } + } + return false; + } + + template <typename OutputIt, typename... Args> + constexpr OutputIt format(OutputIt out, const Args&... args) const { + bool found = (try_format_argument(out, name, args) || ...); + if (!found) { + FMT_THROW(format_error("argument with specified name is not found")); + } + return out; + } +}; + +template <typename Char> +struct is_compiled_format<runtime_named_field<Char>> : std::true_type {}; + +// A replacement field that refers to argument N and has format specifiers. +template <typename Char, typename T, int N> struct spec_field { + using char_type = Char; + formatter<T, Char> fmt; + + template <typename OutputIt, typename... Args> + constexpr FMT_INLINE OutputIt format(OutputIt out, + const Args&... args) const { + const auto& vargs = + fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...); + basic_format_context<OutputIt, Char> ctx(out, vargs); + return fmt.format(get_arg_checked<T, N>(args...), ctx); + } +}; + +template <typename Char, typename T, int N> +struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {}; + +template <typename L, typename R> struct concat { + L lhs; + R rhs; + using char_type = typename L::char_type; + + template <typename OutputIt, typename... Args> + constexpr OutputIt format(OutputIt out, const Args&... args) const { + out = lhs.format(out, args...); + return rhs.format(out, args...); + } +}; + +template <typename L, typename R> +struct is_compiled_format<concat<L, R>> : std::true_type {}; + +template <typename L, typename R> +constexpr concat<L, R> make_concat(L lhs, R rhs) { + return {lhs, rhs}; +} + +struct unknown_format {}; + +template <typename Char> +constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) { + for (size_t size = str.size(); pos != size; ++pos) { + if (str[pos] == '{' || str[pos] == '}') break; + } + return pos; +} + +template <typename Args, size_t POS, int ID, typename S> +constexpr auto compile_format_string(S format_str); + +template <typename Args, size_t POS, int ID, typename T, typename S> +constexpr auto parse_tail(T head, S format_str) { + if constexpr (POS != + basic_string_view<typename S::char_type>(format_str).size()) { + constexpr auto tail = compile_format_string<Args, POS, ID>(format_str); + if constexpr (std::is_same<remove_cvref_t<decltype(tail)>, + unknown_format>()) + return tail; + else + return make_concat(head, tail); + } else { + return head; + } +} + +template <typename T, typename Char> struct parse_specs_result { + formatter<T, Char> fmt; + size_t end; + int next_arg_id; +}; + +enum { manual_indexing_id = -1 }; + +template <typename T, typename Char> +constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str, + size_t pos, int next_arg_id) { + str.remove_prefix(pos); + auto ctx = + compile_parse_context<Char>(str, max_value<int>(), nullptr, next_arg_id); + auto f = formatter<T, Char>(); + auto end = f.parse(ctx); + return {f, pos + fmt::detail::to_unsigned(end - str.data()), + next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()}; +} + +template <typename Char> struct arg_id_handler { + arg_ref<Char> arg_id; + + constexpr int on_auto() { + FMT_ASSERT(false, "handler cannot be used with automatic indexing"); + return 0; + } + constexpr int on_index(int id) { + arg_id = arg_ref<Char>(id); + return 0; + } + constexpr int on_name(basic_string_view<Char> id) { + arg_id = arg_ref<Char>(id); + return 0; + } +}; + +template <typename Char> struct parse_arg_id_result { + arg_ref<Char> arg_id; + const Char* arg_id_end; +}; + +template <int ID, typename Char> +constexpr auto parse_arg_id(const Char* begin, const Char* end) { + auto handler = arg_id_handler<Char>{arg_ref<Char>{}}; + auto arg_id_end = parse_arg_id(begin, end, handler); + return parse_arg_id_result<Char>{handler.arg_id, arg_id_end}; +} + +template <typename T, typename Enable = void> struct field_type { + using type = remove_cvref_t<T>; +}; + +template <typename T> +struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> { + using type = remove_cvref_t<decltype(T::value)>; +}; + +template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID, + typename S> +constexpr auto parse_replacement_field_then_tail(S format_str) { + using char_type = typename S::char_type; + constexpr auto str = basic_string_view<char_type>(format_str); + constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type(); + if constexpr (c == '}') { + return parse_tail<Args, END_POS + 1, NEXT_ID>( + field<char_type, typename field_type<T>::type, ARG_INDEX>(), + format_str); + } else if constexpr (c != ':') { + FMT_THROW(format_error("expected ':'")); + } else { + constexpr auto result = parse_specs<typename field_type<T>::type>( + str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID); + if constexpr (result.end >= str.size() || str[result.end] != '}') { + FMT_THROW(format_error("expected '}'")); + return 0; + } else { + return parse_tail<Args, result.end + 1, result.next_arg_id>( + spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{ + result.fmt}, + format_str); + } + } +} + +// Compiles a non-empty format string and returns the compiled representation +// or unknown_format() on unrecognized input. +template <typename Args, size_t POS, int ID, typename S> +constexpr auto compile_format_string(S format_str) { + using char_type = typename S::char_type; + constexpr auto str = basic_string_view<char_type>(format_str); + if constexpr (str[POS] == '{') { + if constexpr (POS + 1 == str.size()) + FMT_THROW(format_error("unmatched '{' in format string")); + if constexpr (str[POS + 1] == '{') { + return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str); + } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') { + static_assert(ID != manual_indexing_id, + "cannot switch from manual to automatic argument indexing"); + constexpr auto next_id = + ID != manual_indexing_id ? ID + 1 : manual_indexing_id; + return parse_replacement_field_then_tail<get_type<ID, Args>, Args, + POS + 1, ID, next_id>( + format_str); + } else { + constexpr auto arg_id_result = + parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size()); + constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data(); + constexpr char_type c = + arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type(); + static_assert(c == '}' || c == ':', "missing '}' in format string"); + if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) { + static_assert( + ID == manual_indexing_id || ID == 0, + "cannot switch from automatic to manual argument indexing"); + constexpr auto arg_index = arg_id_result.arg_id.val.index; + return parse_replacement_field_then_tail<get_type<arg_index, Args>, + Args, arg_id_end_pos, + arg_index, manual_indexing_id>( + format_str); + } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) { + constexpr auto arg_index = + get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{}); + if constexpr (arg_index != invalid_arg_index) { + constexpr auto next_id = + ID != manual_indexing_id ? ID + 1 : manual_indexing_id; + return parse_replacement_field_then_tail< + decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos, + arg_index, next_id>(format_str); + } else { + if constexpr (c == '}') { + return parse_tail<Args, arg_id_end_pos + 1, ID>( + runtime_named_field<char_type>{arg_id_result.arg_id.val.name}, + format_str); + } else if constexpr (c == ':') { + return unknown_format(); // no type info for specs parsing + } + } + } + } + } else if constexpr (str[POS] == '}') { + if constexpr (POS + 1 == str.size()) + FMT_THROW(format_error("unmatched '}' in format string")); + return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str); + } else { + constexpr auto end = parse_text(str, POS + 1); + if constexpr (end - POS > 1) { + return parse_tail<Args, end, ID>(make_text(str, POS, end - POS), + format_str); + } else { + return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]}, + format_str); + } + } +} + +template <typename... Args, typename S, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +constexpr auto compile(S format_str) { + constexpr auto str = basic_string_view<typename S::char_type>(format_str); + if constexpr (str.size() == 0) { + return detail::make_text(str, 0, 0); + } else { + constexpr auto result = + detail::compile_format_string<detail::type_list<Args...>, 0, 0>( + format_str); + return result; + } +} +#endif // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction) +} // namespace detail + +FMT_BEGIN_EXPORT + +#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction) + +template <typename CompiledFormat, typename... Args, + typename Char = typename CompiledFormat::char_type, + FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)> +FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf, + const Args&... args) { + auto s = std::basic_string<Char>(); + cf.format(std::back_inserter(s), args...); + return s; +} + +template <typename OutputIt, typename CompiledFormat, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)> +constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf, + const Args&... args) { + return cf.format(out, args...); +} + +template <typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +FMT_INLINE std::basic_string<typename S::char_type> format(const S&, + Args&&... args) { + if constexpr (std::is_same<typename S::char_type, char>::value) { + constexpr auto str = basic_string_view<typename S::char_type>(S()); + if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') { + const auto& first = detail::first(args...); + if constexpr (detail::is_named_arg< + remove_cvref_t<decltype(first)>>::value) { + return fmt::to_string(first.value); + } else { + return fmt::to_string(first); + } + } + } + constexpr auto compiled = detail::compile<Args...>(S()); + if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>, + detail::unknown_format>()) { + return fmt::format( + static_cast<basic_string_view<typename S::char_type>>(S()), + std::forward<Args>(args)...); + } else { + return fmt::format(compiled, std::forward<Args>(args)...); + } +} + +template <typename OutputIt, typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) { + constexpr auto compiled = detail::compile<Args...>(S()); + if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>, + detail::unknown_format>()) { + return fmt::format_to( + out, static_cast<basic_string_view<typename S::char_type>>(S()), + std::forward<Args>(args)...); + } else { + return fmt::format_to(out, compiled, std::forward<Args>(args)...); + } +} +#endif + +template <typename OutputIt, typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n, + const S& format_str, Args&&... args) { + auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n), + format_str, std::forward<Args>(args)...); + return {it.base(), it.count()}; +} + +template <typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +FMT_CONSTEXPR20 size_t formatted_size(const S& format_str, + const Args&... args) { + return fmt::format_to(detail::counting_iterator(), format_str, args...) + .count(); +} + +template <typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +void print(std::FILE* f, const S& format_str, const Args&... args) { + memory_buffer buffer; + fmt::format_to(std::back_inserter(buffer), format_str, args...); + detail::print(f, {buffer.data(), buffer.size()}); +} + +template <typename S, typename... Args, + FMT_ENABLE_IF(detail::is_compiled_string<S>::value)> +void print(const S& format_str, const Args&... args) { + print(stdout, format_str, args...); +} + +#if FMT_USE_NONTYPE_TEMPLATE_ARGS +inline namespace literals { +template <detail_exported::fixed_string Str> constexpr auto operator""_cf() { + using char_t = remove_cvref_t<decltype(Str.data[0])>; + return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t), + Str>(); +} +} // namespace literals +#endif + +FMT_END_EXPORT +FMT_END_NAMESPACE + +#endif // FMT_COMPILE_H_ |