libcruft-util/fixed_string.hpp

46 lines
1.2 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2019, Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include <algorithm>
///////////////////////////////////////////////////////////////////////////////
namespace cruft {
/// A simple string-like class that allows constexpr representation of
/// strings.
///
/// This allows strings to be represented as instances of fixed_string in
/// template parameters (rather than using vendor specific array
/// extensions).
template <std::size_t N>
struct fixed_string {
char value[N + 1] {};
static std::size_t size (void) { return N; }
constexpr
fixed_string (char const _value[N+1]) noexcept
{
std::copy_n (_value, N, value);
}
constexpr operator char const* () const { return value; }
constexpr operator std::string_view () const { return value; }
constexpr char const*
c_str (void) const noexcept
{ return value; }
};
template <std::size_t N>
fixed_string (char const (&)[N]) -> fixed_string<N - 1>;
}