forstio/source/forstio/string_literal.h

41 lines
989 B
C++

#pragma once
#include <array>
#include <string_view>
namespace saw {
/**
* Helper object which creates a templated string from the provided string
* literal. It guarantees compile time uniqueness and thus allows using strings
* in template parameters.
*/
template <class CharT, size_t N> class StringLiteral {
public:
constexpr StringLiteral(const CharT (&input)[N]) noexcept {
for (size_t i = 0; i < N; ++i) {
data[i] = input[i];
}
}
std::array<CharT, N> data{};
constexpr std::string_view view() const noexcept {
return std::string_view{data.data()};
}
constexpr bool
operator==(const StringLiteral<CharT, N> &) const noexcept = default;
template <class CharTR, size_t NR>
constexpr bool
operator==(const StringLiteral<CharTR, NR> &) const noexcept {
return false;
}
};
template <typename T, T... Chars>
constexpr StringLiteral<T, sizeof...(Chars)> operator""_key() {
return StringLiteral<T, sizeof...(Chars) + 1u>{Chars..., '\0'};
}
} // namespace saw