automatic conversions to character strings

[John W. Eaton]

As part of eliminating error_state, I just noticed that

  if (arg.is_string ())
    {
      std::string str = arg.string_value ();
      ...
    }
  else
    error ("foobar: arg must be a string");

is NOT the same as

  std::string str = arg.string_value ();

  if (error_state)
    error ("foobar: arg must be a string");
  else
    { ... }

if arg is a numeric value because the string_value extractor attempts to 
convert numbers to strings (possibly with a warning).

Is it time to stop doing these automatic numeric conversions and require 
them to be done explicitly in functions that need that behavior?

I'm beginning to think that value extractors that do implicit 
conversions are kind of evil.

jwe