g-variant-type-first (vtype)

vtype -- a tuple or dictionary entry g-variant-type instance

The first item type of vtype.

Determines the first item type of a tuple or dictionary entry type. This function may only be used with tuple or dictionary entry types, but must not be used with the generic tuple type "r".

In the case of a dictionary entry type, this returns the type of the key. NULL is returned in case of type being "()".

This call, together with the function g-variant-type-next provides an iterator interface over tuple and dictionary entry types.