Convert string to all uppercase leters with std::transform

Question

I'm using transform algorithm and std::toupper to achieve this, but can this be done in one line, like this ?

transform(s.begin(), s.end(), ostream_iterator<string>(cout, "\n"),std::toupper);

I get error on this, so do I have to make a unary function for this and call it with transform or I can use some adaptors ?

Answer 1

Use ostream_iterator<char> instead of ostream_iterator<string>:

transform(s.begin(),s.end(),ostream_iterator<char>(cout,"\n"),std::toupper);

std::transform transforms each character and pass it to the output iterator. That is why the type argument of the output iterator should be char instead of std::string.

By the way, each character will be printed on a newline. Is that what you want? If not, don't pass "\n".

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Note : You may have to use ::toupper instead of std::toupper.

See these

• http://www.ideone.com/x6FB5 (each character on a newline)
• http://www.ideone.com/RcEKn (all characters on the same line)