Q:

Which C/C++ compiler does Xcode use? 

I just started to get my hands dirty with C/C++, and I am still getting my head around the different concepts (I've written mostly Java previously).  I'd really like to know which C/C++ compiler is used and also which standard library is included.  Also, I'd like to know where I can find the API documentation of the respective standard library (like the Java SE API docs). 

A:

For C++:
Xcode 4.6.2 uses the Clang C++ compiler frontend with LLVM as backend which is conform to the C++11 standart and uses libc++ as the standart library.  
Here you can finde a apple presentation about libc++. 

A:

I'm not an XCode user, but it seems to be Apple's LLVM Compiler (by default) according to Apple's website: https://developer.apple.com/technologies/tools/. But, I guess, like any other IDE XCode does support other compilers like GCC.  Also depends on your XCode version it seems: http://useyourloaf.com/blog/2011/03/21/compiler-options-in-xcode-gcc-or-llvm.html
Here's a question in SO that asks about the default compiler and the answer seems to have the code to find just that: In Xcode 4.5, what is "Compiler Default" for "C++ Standard Library" and "C++ Language Dialect"? 
According to this post 4.6 uses clang instead of GCC for C++: http://cplusplusmusings.wordpress.com/2013/02/26/c-and-xcode-4-6/
P.S.: Googling does help ;)

