forked from mirrors/gecko-dev
e2ee2f11df
All present uses of the call-site arguments to MozPromise's methods supply static strings. However, this is nowhere enforced. Do so. Additionally, since this is the third or fourth time the present author alone has personally implemented such an enforcement mechanism, create a helper class to simplify doing so. No functional changes. Differential Revision: https://phabricator.services.mozilla.com/D207462
121 lines
4 KiB
C++
121 lines
4 KiB
C++
/* -*- 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
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef nsTLiteralString_h
|
|
#define nsTLiteralString_h
|
|
|
|
#include "nsTStringRepr.h"
|
|
#include "mozilla/StaticString.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.
|
|
*/
|
|
constexpr const typename raw_type<T, int>::type get() const&& = delete;
|
|
constexpr 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>;
|
|
|
|
namespace mozilla {
|
|
constexpr MOZ_IMPLICIT StaticString::StaticString(nsLiteralCString const& str)
|
|
: mStr(str.get()) {}
|
|
} // namespace mozilla
|
|
|
|
#endif
|