=proto
int duk_get_top(duk_context *ctx);

=summary
<p>Get current stack top (>= 0), indicating the number of values currently on
the value stack (of the current activation).</p>

=example
printf("stack top is %d\n", duk_get_top(ctx));

=tags
stack

=fixme
Return value is an int, unsigned int would be more accurate but probably
inconvenient for calling code (signedness), and would not match
duk_set_top() which takes an int because it allows negative indices.