std::strstreambuf::pcount
std：：strStreambuf：：pcount
| int pcount() const; | | |
|---|
返回写入输出序列的字符数。
如果PUT区域%28的下一个指针std::streambuf::pptr()%29是空指针，返回零。
否则，返回PUT区域中的下一个指针减去PUT区域中的起始指针，即pptr() - pbase()...
参数
%280%29
返回值
写入PUT区域的字符数。
例
二次
#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';
}
二次
产出：
二次
The size of the output is 11 and it holds "Test: 1.23"
1.23
Input-only pcount() = 0
二次
另见
| 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) |
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