---
title: "SE-0114: Updating Buffer \"Value\" Names to \"Header\" Names"
framework: swift-evolution
role: article
path: swift-evolution/0114-buffer-naming
---

# SE-0114: Updating Buffer "Value" Names to "Header" Names

* Proposal: [SE-0114](0114-buffer-naming.md)
* Author: [Erica Sadun](https://github.com/erica)
* Review Manager: [Chris Lattner](https://github.com/lattner)
* Status: **Implemented (Swift 3.0)**
* Decision Notes: [Rationale](https://forums.swift.org/t/accepted-se-0114-updating-buffer-value-names-to-header-names/3359)
* Implementation: [apple/swift#3374](https://github.com/apple/swift/pull/3374)

## Introduction

This proposal updates parameters and generic type parameters from `value` names to `header` names for `ManagedBuffer`, `ManagedProtoBuffer`, and `ManagedBufferPointer`.

All user-facing Swift APIs must go through Swift Evolution. While this is a trivial API change with an existing implementation, this formal proposal provides a paper trail as is normal and usual for this process.

[Swift Evolution Thread](https://forums.swift.org/t/request-for-quickie-proposal-and-review/3175)

[Patch](https://github.com/apple/swift/commit/eb7311de065df7ea332cdde8782cb44f9f4a5121)

## Motivation

This change introduces better semantics for buffer types.

## Detailed Design

This update affects `ManagedBuffer`, `ManagedProtoBuffer`, and `ManagedBufferPointer`.

#### Generic Parameters The generic parameters `<Value, Element>` become `<Header, Element>` in affected classes.

#### Type Members Each use of `value` or `Value` in type members is renamed to `header` or `Header`. Affected members include

* `header: Header` * `_headerPointer`, `_headerOffset` * `withUnsafeMutablePointerToHeader` * `create(minimumCapacity:makingHeaderWith:) -> Header` * Initializers that refer to `makingHeaderWith`

## Impact on Existing Code

Existing third party code will need migration using a simple fixit.

## Alternatives Considered

Not Applicable