std::basic_istream<CharT,Traits>::gcount
From cppreference.com
< cpp | io | basic istream
| std::streamsize gcount() const; |
||
Returns the number of characters extracted by the last unformatted input operation, or the maximum representable value of std::streamsize if the number is not representable.
The following member functions of basic_istream change the value of subsequent gcount() calls:
The following functions set gcount() to zero:
Parameters
(none)
Return value
The number of characters extracted by the last unformatted input operation, or the maximum representable value of std::streamsize if the number is not representable.
Example
Run this code
#include <iostream> #include <sstream> int main() { char x[20]; std::istringstream stream("Hello World"); stream.read(x, sizeof x); std::cout << "Characters extracted: " << stream.gcount(); }
Output:
Characters extracted: 11
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3464 | C++98 | the return value was unspecified when the result overflows | returns the maximum value |