The Tor Browser: comparison mfbt/Char16.h

--1:000000000000
+:aefeee215375
+/* -*- 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/. */
+/* Implements a UTF-16 character type. */
+#ifndef mozilla_Char16_h
+#define mozilla_Char16_h
+#ifdef __cplusplus
+/*
+* C++11 introduces a char16_t type and support for UTF-16 string and character
+* literals. C++11's char16_t is a distinct builtin type. Technically, char16_t
+* is a 16-bit code unit of a Unicode code point, not a "character".
+*/
+#ifdef _MSC_VER
+/*
+* C++11 says char16_t is a distinct builtin type, but Windows's yvals.h
+* typedefs char16_t as an unsigned short. We would like to alias char16_t
+* to Windows's 16-bit wchar_t so we can declare UTF-16 literals as constant
+* expressions (and pass char16_t pointers to Windows APIs). We #define
+* _CHAR16T here in order to prevent yvals.h from overriding our char16_t
+* typedefs, which we set to wchar_t for C++ code.
+*
+* In addition, #defining _CHAR16T will prevent yvals.h from defining a
+* char32_t type, so we have to undo that damage here and provide our own,
+* which is identical to the yvals.h type.
+*/
+#  define MOZ_UTF16_HELPER(s) L##s
+#  define _CHAR16T
+typedef wchar_t char16_t;
+typedef unsigned int char32_t;
+#else
+/* C++11 has a builtin char16_t type. */
+#  define MOZ_UTF16_HELPER(s) u##s
+/**
+* This macro is used to distinguish when char16_t would be a distinct
+* typedef from wchar_t.
+*/
+#  define MOZ_CHAR16_IS_NOT_WCHAR
+#  ifdef WIN32
+#    define MOZ_USE_CHAR16_WRAPPER
+#  endif
+#endif
+#ifdef MOZ_USE_CHAR16_WRAPPER
+# include <string>
+/**
+* Win32 API extensively uses wchar_t, which is represented by a separated
+* builtin type than char16_t per spec. It's not the case for MSVC, but GCC
+* follows the spec. We want to mix wchar_t and char16_t on Windows builds.
+* This class is supposed to make it easier. It stores char16_t const pointer,
+* but provides implicit casts for wchar_t as well. On other platforms, we
+* simply use |typedef const char16_t* char16ptr_t|. Here, we want to make
+* the class as similar to this typedef, including providing some casts that
+* are allowed by the typedef.
+*/
+class char16ptr_t
+{
+private:
+const char16_t* ptr;
+static_assert(sizeof(char16_t) == sizeof(wchar_t), "char16_t and wchar_t sizes differ");
+public:
+char16ptr_t(const char16_t* p) : ptr(p) {}
+char16ptr_t(const wchar_t* p) : ptr(reinterpret_cast<const char16_t*>(p)) {}
+/* Without this, nullptr assignment would be ambiguous. */
+constexpr char16ptr_t(decltype(nullptr)) : ptr(nullptr) {}
+operator const char16_t*() const {
+return ptr;
+}
+operator const wchar_t*() const {
+return reinterpret_cast<const wchar_t*>(ptr);
+}
+operator const void*() const {
+return ptr;
+}
+operator bool() const {
+return ptr != nullptr;
+}
+operator std::wstring() const {
+return std::wstring(static_cast<const wchar_t*>(*this));
+}
+/* Explicit cast operators to allow things like (char16_t*)str. */
+explicit operator char16_t*() const {
+return const_cast<char16_t*>(ptr);
+}
+explicit operator wchar_t*() const {
+return const_cast<wchar_t*>(static_cast<const wchar_t*>(*this));
+}
+explicit operator int() const {
+return reinterpret_cast<intptr_t>(ptr);
+}
+explicit operator unsigned int() const {
+return reinterpret_cast<uintptr_t>(ptr);
+}
+explicit operator long() const {
+return reinterpret_cast<intptr_t>(ptr);
+}
+explicit operator unsigned long() const {
+return reinterpret_cast<uintptr_t>(ptr);
+}
+explicit operator long long() const {
+return reinterpret_cast<intptr_t>(ptr);
+}
+explicit operator unsigned long long() const {
+return reinterpret_cast<uintptr_t>(ptr);
+}
+/**
+* Some Windows API calls accept BYTE* but require that data actually be WCHAR*.
+* Supporting this requires explicit operators to support the requisite explicit
+* casts.
+*/
+explicit operator const char*() const {
+return reinterpret_cast<const char*>(ptr);
+}
+explicit operator const unsigned char*() const {
+return reinterpret_cast<const unsigned char*>(ptr);
+}
+explicit operator unsigned char*() const {
+return const_cast<unsigned char*>(reinterpret_cast<const unsigned char*>(ptr));
+}
+explicit operator void*() const {
+return const_cast<char16_t*>(ptr);
+}
+/* Some operators used on pointers. */
+char16_t operator[](size_t i) const {
+return ptr[i];
+}
+bool operator==(const char16ptr_t &x) const {
+return ptr == x.ptr;
+}
+bool operator==(decltype(nullptr)) const {
+return ptr == nullptr;
+}
+bool operator!=(const char16ptr_t &x) const {
+return ptr != x.ptr;
+}
+bool operator!=(decltype(nullptr)) const {
+return ptr != nullptr;
+}
+char16ptr_t operator+(int aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+char16ptr_t operator+(unsigned int aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+char16ptr_t operator+(long aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+char16ptr_t operator+(unsigned long aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+char16ptr_t operator+(long long aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+char16ptr_t operator+(unsigned long long aValue) const {
+return char16ptr_t(ptr + aValue);
+}
+ptrdiff_t operator-(const char16ptr_t &other) const {
+return ptr - other.ptr;
+}
+};
+inline decltype((char*)0-(char*)0)
+operator-(const char16_t* x, const char16ptr_t y) {
+return x - static_cast<const char16_t*>(y);
+}
+#else
+typedef const char16_t* char16ptr_t;
+#endif
+/*
+* Macro arguments used in concatenation or stringification won't be expanded.
+* Therefore, in order for |MOZ_UTF16(FOO)| to work as expected (which is to
+* expand |FOO| before doing whatever |MOZ_UTF16| needs to do to it) a helper
+* macro, |MOZ_UTF16_HELPER| needs to be inserted in between to allow the macro
+* argument to expand. See "3.10.6 Separate Expansion of Macro Arguments" of the
+* CPP manual for a more accurate and precise explanation.
+*/
+#define MOZ_UTF16(s) MOZ_UTF16_HELPER(s)
+static_assert(sizeof(char16_t) == 2, "Is char16_t type 16 bits?");
+static_assert(char16_t(-1) > char16_t(0), "Is char16_t type unsigned?");
+static_assert(sizeof(MOZ_UTF16('A')) == 2, "Is char literal 16 bits?");
+static_assert(sizeof(MOZ_UTF16("")[0]) == 2, "Is string char 16 bits?");
+#endif
+#endif /* mozilla_Char16_h */

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comparison: mfbt/Char16.h

mfbt/Char16.h