It’s mostly right, but assign properties are still treated the same as they ever were, only weak ones are zeroing. Another caveat is that zeroing weak references are only available in Mac OS X ≥ 10.7 and iOS ≥ 5. While the rest of ARC was backported to 10.6 and iOS 4, weak references cannot … Read more
Most compilers will automatically define: __SSE__ __SSE2__ __SSE3__ __AVX__ __AVX2__ etc, according to whatever command line switches you are passing. You can easily check this with gcc (or gcc-compatible compilers such as clang), like this: $ gcc -msse3 -dM -E – < /dev/null | egrep “SSE|AVX” | sort #define __SSE__ 1 #define __SSE2__ 1 #define … Read more
Although everything bneely said is correct, it doesn’t actually answer your question of how to suppress the warning. If you have to have this code in for some reason (in my case I have HockeyKit in my project and they override a method in a UIImage category [edit: this is no longer the case]) and … Read more
A reliable check is to use the CMAKE_<LANG>_COMPILER_ID variables. E.g., to check the C++ compiler: if (CMAKE_CXX_COMPILER_ID STREQUAL “Clang”) # using Clang elseif (CMAKE_CXX_COMPILER_ID STREQUAL “GNU”) # using GCC elseif (CMAKE_CXX_COMPILER_ID STREQUAL “Intel”) # using Intel C++ elseif (CMAKE_CXX_COMPILER_ID STREQUAL “MSVC”) # using Visual Studio C++ endif() These also work correctly if a compiler wrapper … Read more
Homebrew now has the GCC package so you can install it with this command: brew install gcc
Looks like a Clang bug to me. The general rule is that member functions of the same name in different base classes do not overload. For example: struct Foo { void bar(); }; struct Baz { void bar(int); }; struct Quux : Foo, Baz { }; int main() { Quux().bar(); } // error on both … Read more
As noted below by @thakis, newer versions of Clang (3.5+) accept the -masm=intel argument. For older versions, this should get clang to emit assembly code with Intel syntax: clang++ -S -mllvm –x86-asm-syntax=intel test.cpp You can use -mllvm <arg> to pass in llvm options from the clang command line. Sadly this option doesn’t appear to be … Read more
This is because g++ is not installed, so libstdc++ is not present. You can install g++, or if LLVM is preferred, install LLVM libc++ and specify that you want to use it, like so: sudo apt-get install libc++-dev clang++ -stdlib=libc++ <rest of arguments> You may wish to link /usr/bin/c++ to the default compiler: ln -s … Read more
The correct thing to do, is this… clang -target i686-pc-windows-gnu test.c -otest.exe Or if you want 64bit output… clang -target x86_64-pc-windows-gnu test.c -otest.exe Clang will determine the location of the headers and libraries from your path. Make sure that you only have the version of Mingw in your path that you are targetting. By default, … Read more
As you have found out yourself, the difference between the two options is whether GNU extensions that violates/extend the C++ standard are enabled or not. The GNU C++ extensions are described here. You can also use most of the GNU C extensions (described here) in your C++ programs. It would be also useful to read … Read more