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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/libwebrtc/rtc_base/string_to_number.h | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/rtc_base/string_to_number.h')
-rw-r--r-- | third_party/libwebrtc/rtc_base/string_to_number.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/string_to_number.h b/third_party/libwebrtc/rtc_base/string_to_number.h new file mode 100644 index 0000000000..1d704ee464 --- /dev/null +++ b/third_party/libwebrtc/rtc_base/string_to_number.h @@ -0,0 +1,105 @@ +/* + * Copyright 2017 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#ifndef RTC_BASE_STRING_TO_NUMBER_H_ +#define RTC_BASE_STRING_TO_NUMBER_H_ + +#include <limits> +#include <string> +#include <type_traits> + +#include "absl/strings/string_view.h" +#include "absl/types/optional.h" + +namespace rtc { + +// This file declares a family of functions to parse integers from strings. +// The standard C library functions either fail to indicate errors (atoi, etc.) +// or are a hassle to work with (strtol, sscanf, etc.). The standard C++ library +// functions (std::stoi, etc.) indicate errors by throwing exceptions, which +// are disabled in WebRTC. +// +// Integers are parsed using: +// absl::optional<int-type> StringToNumber(absl::string_view str, +// int base = 10); +// +// These functions parse a value from the beginning of a string into one of the +// fundamental integer types, or returns an empty Optional if parsing +// failed. Values outside of the range supported by the type will be +// rejected. The strings must begin with a digit or a minus sign. No leading +// space nor trailing contents are allowed. +// By setting base to 0, one of octal, decimal or hexadecimal will be +// detected from the string's prefix (0, nothing or 0x, respectively). +// If non-zero, base can be set to a value between 2 and 36 inclusively. + +namespace string_to_number_internal { +// These must be (unsigned) long long, to match the signature of strto(u)ll. +using unsigned_type = unsigned long long; // NOLINT(runtime/int) +using signed_type = long long; // NOLINT(runtime/int) + +absl::optional<signed_type> ParseSigned(absl::string_view str, int base); +absl::optional<unsigned_type> ParseUnsigned(absl::string_view str, int base); + +template <typename T> +absl::optional<T> ParseFloatingPoint(absl::string_view str); +} // namespace string_to_number_internal + +template <typename T> +typename std::enable_if<std::is_integral<T>::value && std::is_signed<T>::value, + absl::optional<T>>::type +StringToNumber(absl::string_view str, int base = 10) { + using string_to_number_internal::signed_type; + static_assert( + std::numeric_limits<T>::max() <= + std::numeric_limits<signed_type>::max() && + std::numeric_limits<T>::lowest() >= + std::numeric_limits<signed_type>::lowest(), + "StringToNumber only supports signed integers as large as long long int"); + absl::optional<signed_type> value = + string_to_number_internal::ParseSigned(str, base); + if (value && *value >= std::numeric_limits<T>::lowest() && + *value <= std::numeric_limits<T>::max()) { + return static_cast<T>(*value); + } + return absl::nullopt; +} + +template <typename T> +typename std::enable_if<std::is_integral<T>::value && + std::is_unsigned<T>::value, + absl::optional<T>>::type +StringToNumber(absl::string_view str, int base = 10) { + using string_to_number_internal::unsigned_type; + static_assert(std::numeric_limits<T>::max() <= + std::numeric_limits<unsigned_type>::max(), + "StringToNumber only supports unsigned integers as large as " + "unsigned long long int"); + absl::optional<unsigned_type> value = + string_to_number_internal::ParseUnsigned(str, base); + if (value && *value <= std::numeric_limits<T>::max()) { + return static_cast<T>(*value); + } + return absl::nullopt; +} + +template <typename T> +typename std::enable_if<std::is_floating_point<T>::value, + absl::optional<T>>::type +StringToNumber(absl::string_view str, int base = 10) { + static_assert( + std::numeric_limits<T>::max() <= std::numeric_limits<long double>::max(), + "StringToNumber only supports floating-point numbers as large " + "as long double"); + return string_to_number_internal::ParseFloatingPoint<T>(str); +} + +} // namespace rtc + +#endif // RTC_BASE_STRING_TO_NUMBER_H_ |