std::boolalpha
STD：：boolalpha，std：：noboolalpha
| Defined in header | | |
|---|---|---|
| std::ios_base& boolalpha( std::ios_base& str | (1) | |
| std::ios_base& noboolalpha( std::ios_base& str | (2) | |
1%29启用boolalpha溪流中的旗子str好像通过打电话str.setf(std::ios_base::boolalpha)
2%29禁用boolalpha溪流中的旗子str好像通过打电话str.unsetf(std::ios_base::boolalpha)
std::boolalpha是I/O操作器，因此可以用表达式调用它，如out << std::boolalpha对任何out类型std::basic_ostream或使用表达式，如in >> std::boolalpha对任何in类型std::basic_istream...
参数
| str | - | reference to I/O stream |
|---|
返回值
str%28操作后对流的引用%29。
例
二次
#include <sstream>
#include <locale>
#include <iostream>
int main()
{
// boolalpha output
std::cout << std::boolalpha
<< "boolalpha true: " << true << '\n'
<< "boolalpha false: " << false << '\n';
std::cout << std::noboolalpha
<< "noboolalpha true: " << true << '\n'
<< "noboolalpha false: " << false << '\n';
// booalpha parse
bool b1, b2;
std::istringstream is("true false"
is >> std::boolalpha >> b1 >> b2;
std::cout << '\"' << is.str() << "\" parsed as " << b1 << ' ' << b2 << '\n';
}
二次
产出：
二次
boolalpha true: true
boolalpha false: false
noboolalpha true: 1
noboolalpha false: 0
"true false" parsed as 1 0
二次
另见
| resetiosflags | clears the specified ios_base flags (function) |
|---|---|
| setiosflags | sets the specified ios_base flags (function) |
| do_truenamedo_falsename virtual | provides the string to use as the name of the boolean true and false (virtual protected member function of std::numpunct) |
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