The Warning module contains a single method named warn, and the module extends itself, making Warning.warn available. #warn is called for all warnings issued by Ruby. By default, warnings are printed to $stderr.
By overriding #warn, you can change how warnings are handled by Ruby, either filtering some warnings, and/or outputting warnings somewhere other than $stderr. When #warn is overridden, super can be called to get the default behavior of printing the warning to $stderr.
Writes warning message msg to $stderr, followed by a newline if the message does not end in a newline. This method is called by Ruby for all emitted warnings.
static VALUE
rb_warning_s_warn(VALUE mod, VALUE str)
{
Check_Type(str, T_STRING);
rb_must_asciicompat(str);
rb_write_error_str(str);
return Qnil;
}
Ruby Core © 1993–2017 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.