Determines if the style attributes of new_match are a closer match
for desc than those of old_match are, or if old_match is null,
determines if new_match is a match at all.
Approximate matching is done for weight and style; other style attributes
must match exactly. Style attributes are all attributes other than family
and size-related attributes. Approximate matching for style considers
pango.types.Style.Oblique and pango.types.Style.Italic as matches, but not as good
a match as when the styles are equal.
Determines if the style attributes of new_match are a closer match for desc than those of old_match are, or if old_match is null, determines if new_match is a match at all.
Approximate matching is done for weight and style; other style attributes must match exactly. Style attributes are all attributes other than family and size-related attributes. Approximate matching for style considers pango.types.Style.Oblique and pango.types.Style.Italic as matches, but not as good a match as when the styles are equal.
Note that old_match must match desc.