The global objectsstd::cin andstd::wcin control input from a stream buffer of implementation-defined type (derived fromstd::streambuf), associated with the standard C input streamstdin.

These objects are guaranteed to be initialized during or before the first time an object of typestd::ios_base::Init is constructed and are available for use in the constructors and destructors of static objects withordered initialization (as long as<iostream> is included before the object is defined).

Unlesssync_with_stdio(false) has been issued, it is safe to concurrently access these objects from multiple threads for both formatted and unformatted input.

Once initialized:

[edit]Notes

The “c” in the name refers to “character” (stroustrup.com FAQ);cin means “character input” andwcin means “wide character input”.

[edit]Example

#include <iostream> struct Foo{int n;    Foo(){std::cout<<"Enter n: ";// no flush needed        std::cin>> n;}}; Foo f;// static object int main(){std::cout<<"f.n is "<< f.n<<'\n';}

Enter n: 10f.n is 10

[edit]See also

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