Defined in header <string_view> | ||
|---|---|---|
template< class CharT, class Traits >
std::basic_ostream<CharT, Traits>&
operator<<( std::basic_ostream<CharT, Traits>& os,
std::basic_string_view<CharT, Traits> v );
| (since C++17) |
Behaves as a FormattedOutputFunction. After constructing and checking the sentry object, determines the output format padding.
Then stores each character from the resulting sequence seq (the contents of v with padding) to the output stream os as if by calling os.rdbuf()->sputn(seq, n), where n is std::max(os.width(), str.size()).
Finally, calls os.width(0) to cancel the effects of std::setw, if any.
May throw std::ios_base::failure if an exception is thrown during output.
| os | - | a character output stream |
| v | - | the view to be inserted |
os.
#include <iomanip>
#include <iostream>
#include <string_view>
int main()
{
constexpr std::string_view s{"abc"};
constexpr int width{5};
// fill/left/right properties are kept until changed
std::cout << std::setfill('-');
std::cout << std::left;
std::cout << '[' << std::setw(width) << s << "]\n";
std::cout << '[' << std::setw(width) << s << "]\n";
std::cout << std::right;
std::cout << '[' << std::setw(width) << s << "]\n";
// width is reset after each call
std::cout << '[' << s << "]\n";
}Output:
[abc--] [abc--] [--abc] [abc]
| performs stream input and output on strings (function template) |
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