运维经–目录
std::boolalpha, std::noboolalpha
1.头文件
#include <ios>
2.原型
std::ios_base& boolalpha( std::ios_base& str );
std::ios_base& noboolalpha( std::ios_base& str );
3.说明
std::boolalpha 是 I/O 操纵符,故可用如 out << std::boolalpha 的表达式对任何 std::basic_ostream 类型的 out ,或用如 in >> std::boolalpha 的表达式对任何 std::basic_istream 类型的 in 调用。
4.范例
#include <sstream>
#include <locale>
#include <iostream>
int main()
{
// boolalpha 输出
std::cout << std::boolalpha
<< "boolalpha true: " << true << '\n'
<< "boolalpha false: " << false << '\n';
std::cout << std::noboolalpha
<< "noboolalpha true: " << true << '\n'
<< "noboolalpha false: " << false << '\n';
// boolalpha 分析
bool b1, b2;
std::istringstream is("true false");
is >> std::boolalpha >> b1 >> b2;
std::cout << '\"' << is.str() << "\" parsed as " << b1 << ' ' << b2 << '\n';
}
输出:
boolalpha true: true
boolalpha false: false
noboolalpha true: 1
noboolalpha false: 0
"true false" parsed as 1 0