# vkEnumerateInstanceExtensionProperties(3) Manual Page

## Name

vkEnumerateInstanceExtensionProperties - Returns up to requested number of global extension properties

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## C Specification

To query the available instance extensions, call:

    // Provided by VK_VERSION_1_0
    VkResult vkEnumerateInstanceExtensionProperties(
        const char*                                 pLayerName,
        uint32_t*                                   pPropertyCount,
        VkExtensionProperties*                      pProperties);

## Parameters

- `pLayerName` is either `NULL` or a pointer to a null-terminated UTF-8 string naming the layer to retrieve extensions from.

- `pPropertyCount` is a pointer to an integer related to the number of extension properties available or queried, as described below.

- `pProperties` is either `NULL` or a pointer to an array of VkExtensionProperties structures.

## Description

When `pLayerName` parameter is `NULL`, only extensions provided by the Vulkan implementation or by implicitly enabled layers are returned. When `pLayerName` is the name of a layer, the instance extensions provided by that layer are returned.

If `pProperties` is `NULL`, then the number of extensions properties available is returned in `pPropertyCount`. Otherwise, `pPropertyCount` must point to a variable set by the application to the number of elements in the `pProperties` array, and on return the variable is overwritten with the number of structures actually written to `pProperties`. If `pPropertyCount` is less than the number of extension properties available, at most `pPropertyCount` structures will be written, and `VK_INCOMPLETE` will be returned instead of `VK_SUCCESS`, to indicate that not all the available properties were returned.

Because the list of available layers may change externally between calls to vkEnumerateInstanceExtensionProperties, two calls may retrieve different results if a `pLayerName` is available in one call but not in another. The extensions supported by a layer may also change between two calls, e.g. if the layer implementation is replaced by a different version between those calls.

Implementations must not advertise any pair of extensions that cannot be enabled together due to behavioral differences, or any extension that cannot be enabled against the advertised version.

Valid Usage (Implicit)

- VUID-vkEnumerateInstanceExtensionProperties-pLayerName-parameter
  If `pLayerName` is not `NULL`, `pLayerName` must be a null-terminated UTF-8 string

- VUID-vkEnumerateInstanceExtensionProperties-pPropertyCount-parameter
  `pPropertyCount` must be a valid pointer to a `uint32_t` value

- VUID-vkEnumerateInstanceExtensionProperties-pProperties-parameter
  If the value referenced by `pPropertyCount` is not `0`, and `pProperties` is not `NULL`, `pProperties` must be a valid pointer to an array of `pPropertyCount` VkExtensionProperties structures

Return Codes

On success, this command returns

  - `VK_SUCCESS`

  - `VK_INCOMPLETE`

On failure, this command returns

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

  - `VK_ERROR_LAYER_NOT_PRESENT`

## See Also

VK_VERSION_1_0, VkExtensionProperties

## Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

## Copyright

Copyright 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0