std::basic_streambuf<CharT,Traits>::setp

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< cpp‎ | io‎ | basic streambuf
 
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std::basic_streambuf
 
protected:
void setp( char_type* pbeg, char_type* pend );

Sets the values of the pointers defining the put area. Specifically, after the call pbase() == pbeg, pptr() == pbeg, epptr() == pend.

Parameters

pbeg - pointer to the new beginning of the put area
pend - pointer to the new end of the put area

Return value

(none)

Example

Run this code
#include <array>
#include <cstddef>
#include <iostream>
 
// Buffer for std::ostream implemented by std::array
template<std::size_t size, class CharT = char>
struct ArrayedStreamBuffer : std::basic_streambuf<CharT>
{
    using Base = std::basic_streambuf<CharT>;
    using char_type = typename Base::char_type;
 
    ArrayedStreamBuffer()
    {
        // put area pointers to work with 'buffer'
        Base::setp(buffer.data(), buffer.data() + size);
    }
 
    void print_buffer()
    {
        for (char_type i : buffer)
        {
            if (i == 0)
                std::cout << "\\0";
            else
                std::cout << i;
            std::cout << ' ';
        }
        std::cout << '\n';
    }
 
private:
    std::array<char_type, size> buffer{}; // value-initialize buffer
};
 
int main()
{
    ArrayedStreamBuffer<10> streambuf;
    std::ostream stream(&streambuf);
 
    stream << "hello";
    stream << ",";
 
    streambuf.print_buffer();
}

Output: 

h e l l o , \0 \0 \0 \0

See also

 repositions the beginning, next, and end pointers of the input sequence
(protected member function)
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