---
name: Sub::Util
runtime: pp
source: src/native/Sub/Util/pp.rs
---
```{index} single: Sub::Util; Perl module (pp runtime)
```

# Sub::Util

Native implementation of Sub::Util

Provides subroutine utility functions for introspection and manipulation.

# Synopsis

    use Sub::Util qw(subname set_subname);

    my $name = subname(\&foo);    # "main::foo"

    my $anon = sub { ... };
    set_subname("MyPkg::handler", $anon);

# Functions

## subname

Return the fully qualified name of a subroutine reference (e.g. "main::foo").
Dies if the argument is not a code reference.

```perl
use Sub::Util 'subname';
my $name = subname(\&foo);  # "main::foo"
```

## set_subname

Set the name of a subroutine reference. Mutates the CV in-place and returns
the same reference. Unqualified names are placed in the "main::" namespace.

```perl
use Sub::Util 'set_subname';
my $sub = set_subname("MyPkg::renamed", \&original);
```

## prototype

Return the prototype string of a subroutine, or undef if no prototype is set.

```perl
use Sub::Util 'prototype';
my $proto = prototype(\&mysub);  # e.g. "$$" or undef
```

## set_prototype

Set or remove the prototype of a subroutine reference. Pass undef to remove
the prototype. Mutates the CV in-place and returns the same reference.

```perl
use Sub::Util 'set_prototype';
set_prototype('$$', \&mysub);
set_prototype(undef, \&mysub);  # remove prototype
```

Perl equivalent: Sub::Util (part of Scalar-List-Utils distribution)