c++-standard-library

In C++ it is impossible to implement certain C++ standard library type traits without compiler intrinsics, using the C++ language only. Traits deal directly with C++ types. According to §17.6.1.3.2 freestanding implementations of the C++ standard library must implement <type_traits> . Doesn't this effectively mean that the C++ standard requires non-standard language extensions/compiler intrinsics from all compilers which support want to support freestanding C++ standard library implementations? Why were such type traits allowed into the standard without support in the core language? There are

I've built and installed (under the prefix ~/alt ) LLVM-Clang trunk (23 apr 2012) successfully using GCC-4.6 on Ubuntu 12.04 and in turn libc++ using this Clang-build. When I want to use it I have to supply both -lc++ and -libstdc++ as follows /home/per/alt/bin/clang -x c++ -I/home/per/alt/include/v1 -L/home/per/alt/lib -std=gnu++0x -g -Wall ~/f.cpp -lm -lc++ -lstdc++ -lpthread -o f to compile f.cpp containing #include <iostream> using std::cout; using std::endl; int main(int argc, const char * argv[]) { cout << "sxx" << endl; return 0; } If I omit -lstdc++ I get the link error /home/per/alt

This question already has answers here : Closed 8 years ago . Possible Duplicate: What's this STL vs. “C++ Standard Library” fight all about? I am very much used to the term STL ("Standard Template Library") and I catch myself often using it when I really mean the C++ Standard Library . So, since almost everything in the C++(-11) Standard Library is a template nowadays, I wonder: Is there a definition what is STL and what is not, in the C++Standard-Lib? Maybe containers, streams, algorithms, etc? Or should I just stop using the term "STL", because it's the historic one that SGI (correct?) used

While reading the examples of std::hash used for std::unordered_map, I noticed that the operator() function was being accessed by {}. http://en.cppreference.com/w/cpp/utility/hash result_type operator()(argument_type const& s) const { result_type const h1 ( std::hash<std::string>{}(s.first_name) ); result_type const h2 ( std::hash<std::string>{}(s.last_name) ); return h1 ^ (h2 << 1); // or use boost::hash_combine (see Discussion) } What does the use of {} here represent? std::hash<T> is a type not a function. An instance of std::hash has an operator() that does the hash. So std::hash<std:

I have a class field which is a std::vector. I know how many elements I want this vector to contain: N. How do I initialize the vector with N elements? std::vector has a constructor declared as: vector(size_type N, const T& x = T()); You can use it to construct the std::vector containing N copies of x . The default value for x is a value initialized T (if T is a class type with a default constructor then value initialization is default construction). It's straightforward to initialize a std::vector data member using this constructor: struct S { std::vector<int> x; S() : x(15) { } } class

Environment: Windows XP. Visual Studios 2010. Language - C++. I have run into the following link error & have run out of ideas how to fix this problem. I have a project (CnD Device) which links to 2 projects (Messages & Carbon) controlled by my group. I have tried to search for project properties between the 3 projects enter tcp_driver.obj : error LNK2019: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl toString(int)" (?toString@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@H@Z) referenced in