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std::strstreambuf::pcount

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< cpp‎ | io‎ | strstreambuf
Revision as of 14:02, 26 August 2013 by Cubbi (Talk | contribs)

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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()

Contents

[edit] Parameters

(none)

[edit] Return value

The number of characters written to the put area.

[edit] Example

#include <strstream>
#include <iostream>
 
int main()
{
    std::strstream dyn; // dynamically-allocated output buffer
    dyn << "Test: " << 1.23;
    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 10 and it holds "Test: 1.23"
1.23
Input-only pcount() = 0

[edit] See also

obtains the number of characters written
(public member function of std::strstream) [edit]
obtains the number of characters written
(public member function of std::ostrstream) [edit]