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/*
* Copyright 2015-2020 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef TEMPLATE_STRING_HXX
#define TEMPLATE_STRING_HXX
#include "StringView.hxx"
#include <array> // for std::size()
#include <cstddef>
#include <string_view>
namespace TemplateString {
template<std::size_t _size>
struct Buffer {
static constexpr std::size_t size = _size;
char value[size + 1];
constexpr operator const char *() const noexcept {
return value;
}
constexpr operator std::string_view() const noexcept {
return {value, size};
}
constexpr operator StringView() const noexcept {
return {value, size};
}
};
/**
* An empty string.
*/
constexpr auto
Empty() noexcept
{
return Buffer<0>{};
}
/**
* A string consisting of a single character.
*/
constexpr auto
FromChar(char ch) noexcept
{
Buffer<1> result{};
result.value[0] = ch;
return result;
}
namespace detail {
constexpr auto
size(const char &) noexcept
{
return 1;
}
constexpr const char *
data(const char &ch) noexcept
{
return &ch;
}
template<std::size_t s>
constexpr auto
size(const Buffer<s> &b) noexcept
{
return b.size;
}
template<std::size_t size>
constexpr const char *
data(const Buffer<size> &b) noexcept
{
return b.value;
}
constexpr char *
copy_n(const char *src, std::size_t n, char *dest) noexcept
{
for (std::size_t i = 0; i < n; ++i)
dest[i] = src[i];
return dest + n;
}
}
/**
* A string consisting of a single character.
*/
template<std::size_t size>
constexpr auto
FromLiteral(const char (&src)[size]) noexcept
{
Buffer<size - 1> result{};
detail::copy_n(src, result.size, result.value);
return result;
}
template<typename... Args>
constexpr auto
Concat(Args... args) noexcept
{
using std::size;
using std::data;
using detail::size;
using detail::data;
using detail::copy_n;
constexpr std::size_t total_size = (std::size_t(0) + ... + size(args));
Buffer<total_size> result{};
char *p = result.value;
((p = copy_n(data(args), size(args), p)), ...);
return result;
}
} // namespace TemplateString
#endif