Link to PR78710

Background

Nicolai Josuttis 2016-12-07 13:46:36 UTC
stoi("hello") currently throws an exception where what() only outputs "stoi"
(nothing else).

The reason is (if I analyzed it correctly):

• stoi etc. pass their name (just "stoi") to __stoa as __name
• __stoa calls:
      std::_throw_invalid_argument(_name);
• which usually seems to call _GLIBCXX_THROW_OR_ABORT

Some component (either __stoa() or __throw_invalid_argument())
should extend the message at least a bit.
E.g. __stoa() might call
       std::__throw_invalid_argument("invalid argument for " + __name)
(using a valid syntax of course).