ralpha-assets/Plugins/CesiumForUnreal/Source/ThirdParty/include/ada/checkers-inl.h

68 lines
2.1 KiB
C++

/**
* @file checkers-inl.h
* @brief Definitions for URL specific checkers used within Ada.
*/
#ifndef ADA_CHECKERS_INL_H
#define ADA_CHECKERS_INL_H
#include "ada/common_defs.h"
#include <algorithm>
#include <string_view>
#include <cstring>
namespace ada::checkers {
inline bool has_hex_prefix_unsafe(std::string_view input) {
// This is actually efficient code, see has_hex_prefix for the assembly.
uint32_t value_one = 1;
bool is_little_endian = (reinterpret_cast<char*>(&value_one)[0] == 1);
uint16_t word0x{};
std::memcpy(&word0x, "0x", 2); // we would use bit_cast in C++20 and the
// function could be constexpr.
uint16_t two_first_bytes{};
std::memcpy(&two_first_bytes, input.data(), 2);
if (is_little_endian) {
two_first_bytes |= 0x2000;
} else {
two_first_bytes |= 0x020;
}
return two_first_bytes == word0x;
}
inline bool has_hex_prefix(std::string_view input) {
return input.size() >= 2 && has_hex_prefix_unsafe(input);
}
constexpr bool is_digit(char x) noexcept { return (x >= '0') & (x <= '9'); }
constexpr char to_lower(char x) noexcept { return (x | 0x20); }
constexpr bool is_alpha(char x) noexcept {
return (to_lower(x) >= 'a') && (to_lower(x) <= 'z');
}
inline constexpr bool is_windows_drive_letter(std::string_view input) noexcept {
return input.size() >= 2 &&
(is_alpha(input[0]) && ((input[1] == ':') || (input[1] == '|'))) &&
((input.size() == 2) || (input[2] == '/' || input[2] == '\\' ||
input[2] == '?' || input[2] == '#'));
}
inline constexpr bool is_normalized_windows_drive_letter(
std::string_view input) noexcept {
return input.size() >= 2 && (is_alpha(input[0]) && (input[1] == ':'));
}
ada_really_inline bool begins_with(std::string_view view,
std::string_view prefix) {
// in C++20, you have view.begins_with(prefix)
// std::equal is constexpr in C++20
return view.size() >= prefix.size() &&
std::equal(prefix.begin(), prefix.end(), view.begin());
}
} // namespace ada::checkers
#endif // ADA_CHECKERS_INL_H