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std::strstreambuf::pcount(3) C++ Standard Libary std::strstreambuf::pcount(3)

NAME

std::strstreambuf::pcount - std::strstreambuf::pcount

Synopsis


int pcount() const;


Returns the number of characters written to the output sequence.


If the next pointer for the put area (std::streambuf::pptr()) is a null pointer,
returns zero.


Otherwise, returns the next pointer in the put area minus the beginning pointer in
the put area, that is pptr() - pbase()

Parameters


(none)

Return value


The number of characters written to the put area.

Example

// Run this code


#include <strstream>
#include <iostream>


int main()
{
std::strstream dyn; // dynamically-allocated output buffer
dyn << "Test: " << 1.23 << std::ends;
std::strstreambuf* buf = dyn.rdbuf();
std::cout << "The size of the output is "
<< buf->pcount() // or just buf.pcount()
<< " and it holds \"" << dyn.str() << "\"\n";
dyn.freeze(false); // after calling .str() on a dynamic strstream


char arr[10];
std::ostrstream user(arr, 10); // user-provided output buffer
buf = user.rdbuf();
user << 1.23; // note: no std::ends
std::cout.write(arr, buf->pcount()); // or just user.pcount()
std::cout << '\n';


std::istrstream lit("1 2 3"); // read-only fixed-size buffer
buf = lit.rdbuf();
// istrstream has no member pcount(), so lit.pcount() won't work
std::cout << "Input-only pcount() = " << buf->pcount() << '\n';
}

Output:


The size of the output is 11 and it holds "Test: 1.23"
1.23
Input-only pcount() = 0

See also


pcount obtains the number of characters written
(public member function of std::strstream)
pcount obtains the number of characters written
(public member function of std::ostrstream)

2022.07.31 http://cppreference.com