Ruby

Float(arg) → float
Returns arg converted to a float. Numeric types are converted directly, the rest are converted using arg.to_f. Converting nil generates a TypeError.

Strings are NOT converted using arg.to_f

'123_INVALID'.to_f 
# => 123.0

Float('123_INVALID') 
# => ArgumentError

This could be fixed by changing object.c like so:

-       return DBL2NUM(rb_str_to_dbl(val, TRUE));
+       return DBL2NUM(rb_str_to_dbl(val, FALSE));

But it appears that this is desired behavior as there are many specs to ensure this strict validity checking. Please update the documentation to reflect this.

Thanks,

Brian