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Diffstat (limited to 'src/google/protobuf/stubs/casts.h')
| -rw-r--r-- | src/google/protobuf/stubs/casts.h | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/src/google/protobuf/stubs/casts.h b/src/google/protobuf/stubs/casts.h deleted file mode 100644 index be652849..00000000 --- a/src/google/protobuf/stubs/casts.h +++ /dev/null @@ -1,133 +0,0 @@ -// Protocol Buffers - Google's data interchange format -// Copyright 2014 Google Inc. All rights reserved. -// https://developers.google.com/protocol-buffers/ -// -// 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. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// 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 COPYRIGHT -// OWNER 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 GOOGLE_PROTOBUF_CASTS_H__ -#define GOOGLE_PROTOBUF_CASTS_H__ - -#include <google/protobuf/stubs/common.h> -#include <google/protobuf/stubs/type_traits.h> - -namespace google { -namespace protobuf { -namespace internal { -// Use implicit_cast as a safe version of static_cast or const_cast -// for upcasting in the type hierarchy (i.e. casting a pointer to Foo -// to a pointer to SuperclassOfFoo or casting a pointer to Foo to -// a const pointer to Foo). -// When you use implicit_cast, the compiler checks that the cast is safe. -// Such explicit implicit_casts are necessary in surprisingly many -// situations where C++ demands an exact type match instead of an -// argument type convertable to a target type. -// -// The From type can be inferred, so the preferred syntax for using -// implicit_cast is the same as for static_cast etc.: -// -// implicit_cast<ToType>(expr) -// -// implicit_cast would have been part of the C++ standard library, -// but the proposal was submitted too late. It will probably make -// its way into the language in the future. -template<typename To, typename From> -inline To implicit_cast(From const &f) { - return f; -} - -// When you upcast (that is, cast a pointer from type Foo to type -// SuperclassOfFoo), it's fine to use implicit_cast<>, since upcasts -// always succeed. When you downcast (that is, cast a pointer from -// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because -// how do you know the pointer is really of type SubclassOfFoo? It -// could be a bare Foo, or of type DifferentSubclassOfFoo. Thus, -// when you downcast, you should use this macro. In debug mode, we -// use dynamic_cast<> to double-check the downcast is legal (we die -// if it's not). In normal mode, we do the efficient static_cast<> -// instead. Thus, it's important to test in debug mode to make sure -// the cast is legal! -// This is the only place in the code we should use dynamic_cast<>. -// In particular, you SHOULDN'T be using dynamic_cast<> in order to -// do RTTI (eg code like this: -// if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo); -// if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo); -// You should design the code some other way not to need this. - -template<typename To, typename From> // use like this: down_cast<T*>(foo); -inline To down_cast(From* f) { // so we only accept pointers - // Ensures that To is a sub-type of From *. This test is here only - // for compile-time type checking, and has no overhead in an - // optimized build at run-time, as it will be optimized away - // completely. - if (false) { - implicit_cast<From*, To>(0); - } - -#if !defined(NDEBUG) && !defined(GOOGLE_PROTOBUF_NO_RTTI) - assert(f == NULL || dynamic_cast<To>(f) != NULL); // RTTI: debug mode only! -#endif - return static_cast<To>(f); -} - -template<typename To, typename From> // use like this: down_cast<T&>(foo); -inline To down_cast(From& f) { - typedef typename remove_reference<To>::type* ToAsPointer; - // Ensures that To is a sub-type of From *. This test is here only - // for compile-time type checking, and has no overhead in an - // optimized build at run-time, as it will be optimized away - // completely. - if (false) { - implicit_cast<From*, ToAsPointer>(0); - } - -#if !defined(NDEBUG) && !defined(GOOGLE_PROTOBUF_NO_RTTI) - // RTTI: debug mode only! - assert(dynamic_cast<ToAsPointer>(&f) != NULL); -#endif - return *static_cast<ToAsPointer>(&f); -} - -template<typename To, typename From> -inline To bit_cast(const From& from) { - GOOGLE_COMPILE_ASSERT(sizeof(From) == sizeof(To), - bit_cast_with_different_sizes); - To dest; - memcpy(&dest, &from, sizeof(dest)); - return dest; -} - -} // namespace internal - -// We made these internal so that they would show up as such in the docs, -// but we don't want to stick "internal::" in front of them everywhere. -using internal::implicit_cast; -using internal::down_cast; -using internal::bit_cast; - -} // namespace protobuf -} // namespace google -#endif // GOOGLE_PROTOBUF_CASTS_H__ |