Returns a boolean indicating whether the SV is derived from the specified class at the C level. To check derivation at the Perl level, call isa() as a normal Perl method.

Currently, the only significant value for flags is SVf_UTF8.

Exactly like "sv_derived_from_pvn", but takes the name string in the form of an SV instead of a string/length pair. This is the advised form.

Exactly like "sv_derived_from_pv", but doesn't take a flags parameter.

Exactly like "sv_derived_from_pvn", but takes a nul-terminated string instead of a string/length pair.

Exactly like "sv_derived_from_pvn", but takes the name string as the HvNAME of the given HV (which would presumably represent a stash).

Returns a boolean indicating whether the SV is an object reference and is derived from the specified class, respecting any isa() method overloading it may have. Returns false if sv is not a reference to an object, or is not derived from the specified class.

This is the function used to implement the behaviour of the isa operator.

Does not invoke magic on sv.

Not to be confused with the older sv_isa function, which does not use an overloaded isa() method, nor will check subclassing.

Returns a boolean indicating whether the SV performs a specific, named role. The SV can be a Perl object or the name of a Perl class.

Like "sv_does_pv", but doesn't take a flags parameter.

Like "sv_does_sv", but takes a nul-terminated string instead of an SV.

Like "sv_does_sv", but takes a string/length pair instead of an SV.

A specialised variant of croak() for emitting the usage message for xsubs

    croak_xs_usage(cv, "eee_yow");

works out the package name and subroutine name from cv, and then calls croak(). Hence if cv is &ouch::awk, it would call croak as:

 Perl_croak(aTHX_ "Usage: %" SVf "::%" SVf "(%s)", "ouch" "awk",
                                                     "eee_yow");