c/c++ reference ，很全面
C/C++ ReferenceGeneral C/C++Pre-processor commands Operator Precedence Escape Sequences ASCII Chart Data Types Keywords Standard C LibraryStandard C I/O Standard C String & Character Standard C Math Standard C Time & Date Standard C Memory Other standard C functions All C Functions
C++C++ I/O C++ Strings Miscellaneous C++ C++ Standard Template LibraryC++ Algorithms C++ Vectors C++ Double-Ended Queues C++ Lists C++ Priority Queues C++ Queues C++ Stacks C++ Sets C++ Multisets C++ Maps C++ Multimaps C++ Bitsets