std::cin, std::wcin
| Defined in header <iostream>
|
||
| extern std::istream cin; |
(1) | |
| extern std::wistream wcin; |
(2) | |
The global objects std::cin and std::wcin control input from a stream buffer of implementation-defined type (derived from std::streambuf), associated with the standard C input stream stdin.
These objects are guaranteed to be initialized during or before the first time an object of type std::ios_base::Init is constructed and are available for use in the constructors and destructors of static objects with ordered initialization (as long as <iostream> is included before the object is defined).
Unless sync_with_stdio(false) has been issued, it is safe to concurrently access these objects from multiple threads for both formatted and unformatted input.
Once std::cin is constructed, std::cin.tie() returns &std::cout, and likewise, std::wcin.tie() returns &std::wcout. This means that any formatted input operation on std::cin forces a call to std::cout.flush() if any characters are pending for output.
Notes
The 'c' in the name refers to "character" (stroustrup.com FAQ); cin means "character input" and wcin means "wide character input".
Example
Possible output:
Enter n: 10 f.n is 10
See also
| initializes standard stream objects (public member class of std::ios_base) | |
| writes to the standard C output stream stdout (global object) | |
| expression of type FILE* associated with the input stream expression of type FILE* associated with the output stream expression of type FILE* associated with the error output stream (macro constant) |