---
description: "Learn more about the inline_recursion pragma directive in Microsoft C/C++"
title: "inline_recursion pragma"
ms.date: 01/22/2021
f1_keywords: ["inline_recursion_CPP", "vc-pragma.inline_recursion"]
helpviewer_keywords: ["pragma, inline_recursion", "inline_recursion pragma"]
no-loc: ["pragma"]
---
# `inline_recursion` pragma

Controls the inline expansion of direct or mutually recursive function calls.

## Syntax

> **`#pragma inline_recursion(`** [ { **`on`** | **`off`** } ] **`)`**

## Remarks

Use this pragma to control functions marked as [`inline`](../cpp/inline-functions-cpp.md) and [`__inline`](../cpp/inline-functions-cpp.md) or functions that the compiler automatically expands under the **`/Ob2`** option. Use of this pragma requires an [`/Ob`](../build/reference/ob-inline-function-expansion.md) compiler option setting of either 1 or 2. The default state for **`inline_recursion`** is off. This pragma takes effect at the first function call after the pragma is seen and doesn't affect the definition of the function.

The **`inline_recursion`** pragma controls how recursive functions are expanded. If **`inline_recursion`** is off, and if an inline function calls itself, either directly or indirectly, the function is expanded only one time. If **`inline_recursion`** is on, the function is expanded multiple times until it reaches the value set with the [`inline_depth`](../preprocessor/inline-depth.md) pragma, the default value for recursive functions that is defined by the `inline_depth` pragma, or a capacity limit.

## See also

[Pragma directives and the `__pragma` and `_Pragma` keywords](./pragma-directives-and-the-pragma-keyword.md)\
[`inline_depth`](../preprocessor/inline-depth.md)\
[`/Ob` (Inline function expansion)](../build/reference/ob-inline-function-expansion.md)