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/*
* 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.
*/
#include "rtc_base/string_to_number.h"
#include <ctype.h>
#include <cerrno>
#include <cstdlib>
#include "rtc_base/checks.h"
namespace rtc {
namespace string_to_number_internal {
absl::optional<signed_type> ParseSigned(const char* str, int base) {
RTC_DCHECK(str);
if (isdigit(str[0]) || str[0] == '-') {
char* end = nullptr;
errno = 0;
const signed_type value = std::strtoll(str, &end, base);
if (end && *end == '\0' && errno == 0) {
return value;
}
}
return absl::nullopt;
}
absl::optional<unsigned_type> ParseUnsigned(const char* str, int base) {
RTC_DCHECK(str);
if (isdigit(str[0]) || str[0] == '-') {
// Explicitly discard negative values. std::strtoull parsing causes unsigned
// wraparound. We cannot just reject values that start with -, though, since
// -0 is perfectly fine, as is -0000000000000000000000000000000.
const bool is_negative = str[0] == '-';
char* end = nullptr;
errno = 0;
const unsigned_type value = std::strtoull(str, &end, base);
if (end && *end == '\0' && errno == 0 && (value == 0 || !is_negative)) {
return value;
}
}
return absl::nullopt;
}
template <typename T>
T StrToT(const char* str, char** str_end);
template <>
inline float StrToT(const char* str, char** str_end) {
return std::strtof(str, str_end);
}
template <>
inline double StrToT(const char* str, char** str_end) {
return std::strtod(str, str_end);
}
template <>
inline long double StrToT(const char* str, char** str_end) {
return std::strtold(str, str_end);
}
template <typename T>
absl::optional<T> ParseFloatingPoint(const char* str) {
RTC_DCHECK(str);
if (*str == '\0')
return absl::nullopt;
char* end = nullptr;
errno = 0;
const T value = StrToT<T>(str, &end);
if (end && *end == '\0' && errno == 0) {
return value;
}
return absl::nullopt;
}
template absl::optional<float> ParseFloatingPoint(const char* str);
template absl::optional<double> ParseFloatingPoint(const char* str);
template absl::optional<long double> ParseFloatingPoint(const char* str);
} // namespace string_to_number_internal
} // namespace rtc
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