# PR_IMPLEMENT

Used to define implementations of symbols that are to be exported from a
shared library.

## Syntax

```{code}
#include <prtypes.h>

PR_IMPLEMENT(type)implementation
```

## Description

{ref}`PR_IMPLEMENT` is used to define implementations of externally visible
routines and globals. For syntax details for each platform, see
{searchfox}`prtypes.h <nsprpub/pr/include/prtypes.h>`.

:::{warning}
**Warning**: Some platforms do not allow the use of the underscore
character (\_) as the first character of an exported symbol.
:::