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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#ifndef nsTLiteralString_h
#define nsTLiteralString_h
#include "nsTStringRepr.h"
/**
* nsTLiteralString_CharT
*
* Stores a null-terminated, immutable sequence of characters.
*
* nsTString-lookalike that restricts its string value to a literal character
* sequence. Can be implicitly cast to const nsTString& (the const is
* essential, since this class's data are not writable). The data are assumed
* to be static (permanent) and therefore, as an optimization, this class
* does not have a destructor.
*/
template <typename T>
class nsTLiteralString : public mozilla::detail::nsTStringRepr<T> {
public:
typedef nsTLiteralString<T> self_type;
#ifdef __clang__
// bindgen w/ clang 3.9 at least chokes on a typedef, but using is okay.
using typename mozilla::detail::nsTStringRepr<T>::base_string_type;
#else
// On the other hand msvc chokes on the using statement. It seems others
// don't care either way so we lump them in here.
typedef typename mozilla::detail::nsTStringRepr<T>::base_string_type
base_string_type;
#endif
typedef typename base_string_type::char_type char_type;
typedef typename base_string_type::size_type size_type;
typedef typename base_string_type::DataFlags DataFlags;
typedef typename base_string_type::ClassFlags ClassFlags;
public:
/**
* constructor
*/
template <size_type N>
explicit constexpr nsTLiteralString(const char_type (&aStr)[N])
: nsTLiteralString(aStr, N - 1) {}
nsTLiteralString(const nsTLiteralString&) = default;
/**
* For compatibility with existing code that requires const ns[C]String*.
* Use sparingly. If possible, rewrite code to use const ns[C]String&
* and the implicit cast will just work.
*/
const nsTString<T>& AsString() const MOZ_LIFETIME_BOUND {
return *reinterpret_cast<const nsTString<T>*>(this);
}
operator const nsTString<T>&() const MOZ_LIFETIME_BOUND { return AsString(); }
template <typename N, typename Dummy>
struct raw_type {
typedef N* type;
};
#ifdef MOZ_USE_CHAR16_WRAPPER
template <typename Dummy>
struct raw_type<char16_t, Dummy> {
typedef char16ptr_t type;
};
#endif
/**
* Prohibit get() on temporaries as in "x"_ns.get().
* These should be written as just "x", using a string literal directly.
*/
const typename raw_type<T, int>::type get() const&& = delete;
const typename raw_type<T, int>::type get() const& { return this->mData; }
// At least older gcc versions do not accept these friend declarations,
// complaining about an "invalid argument list" here, but not where the actual
// operators are defined or used. We make the supposed-to-be-private constructor
// public when building with gcc, relying on the default clang builds to fail if
// any non-private use of that constructor would get into the codebase.
#if defined(__clang__)
private:
friend constexpr auto operator"" _ns(const char* aStr, std::size_t aLen);
friend constexpr auto operator"" _ns(const char16_t* aStr, std::size_t aLen);
#else
public:
#endif
// Only for use by operator""
constexpr nsTLiteralString(const char_type* aStr, size_t aLen)
: base_string_type(const_cast<char_type*>(aStr), aLen,
DataFlags::TERMINATED | DataFlags::LITERAL,
ClassFlags::NULL_TERMINATED) {}
public:
// NOT TO BE IMPLEMENTED
template <size_type N>
nsTLiteralString(char_type (&aStr)[N]) = delete;
nsTLiteralString& operator=(const nsTLiteralString&) = delete;
};
extern template class nsTLiteralString<char>;
extern template class nsTLiteralString<char16_t>;
#endif