---
title: CLanguageStandard
framework: swift-package-manager
role: symbol
role_heading: Enumeration
path: swift-package-manager/documentation/packagedescription/clanguagestandard
---

# CLanguageStandard

The supported C language standard you use to compile C sources in the package.

## Declaration

```swift
enum CLanguageStandard
```

## Topics

### Enumeration Cases

- [CLanguageStandard.c11](swift-package-manager/documentation/packagedescription/clanguagestandard/c11.md)
- [CLanguageStandard.c17](swift-package-manager/documentation/packagedescription/clanguagestandard/c17.md)
- [CLanguageStandard.c18](swift-package-manager/documentation/packagedescription/clanguagestandard/c18.md)
- [CLanguageStandard.c2x](swift-package-manager/documentation/packagedescription/clanguagestandard/c2x.md)
- [CLanguageStandard.c89](swift-package-manager/documentation/packagedescription/clanguagestandard/c89.md)
- [CLanguageStandard.c90](swift-package-manager/documentation/packagedescription/clanguagestandard/c90.md)
- [CLanguageStandard.c99](swift-package-manager/documentation/packagedescription/clanguagestandard/c99.md)
- [CLanguageStandard.gnu11](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu11.md)
- [CLanguageStandard.gnu17](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu17.md)
- [CLanguageStandard.gnu18](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu18.md)
- [CLanguageStandard.gnu2x](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu2x.md)
- [CLanguageStandard.gnu89](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu89.md)
- [CLanguageStandard.gnu90](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu90.md)
- [CLanguageStandard.gnu99](swift-package-manager/documentation/packagedescription/clanguagestandard/gnu99.md)
- [CLanguageStandard.iso9899_1990](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_1990.md)
- [CLanguageStandard.iso9899_199409](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_199409.md)
- [CLanguageStandard.iso9899_1999](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_1999.md)
- [CLanguageStandard.iso9899_2011](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_2011.md)
- [CLanguageStandard.iso9899_2017](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_2017.md)
- [CLanguageStandard.iso9899_2018](swift-package-manager/documentation/packagedescription/clanguagestandard/iso9899_2018.md)

### Hashing

- [hash(into:)](swift-package-manager/documentation/packagedescription/clanguagestandard/hash(into:).md)
- [hashValue](swift-package-manager/documentation/packagedescription/clanguagestandard/hashvalue.md)

### Operator Functions

- [!=(_:_:)](swift-package-manager/documentation/packagedescription/clanguagestandard/!=(_:_:).md)

### Creating a Value

- [init(rawValue:)](swift-package-manager/documentation/packagedescription/clanguagestandard/init(rawvalue:).md)

### Default Implementations

- [Equatable Implementations](swift-package-manager/documentation/packagedescription/clanguagestandard/equatable-implementations.md)
- [RawRepresentable Implementations](swift-package-manager/documentation/packagedescription/clanguagestandard/rawrepresentable-implementations.md)

## Relationships

### Conforms To

- Swift.Equatable
- Swift.Hashable
- Swift.RawRepresentable

## See Also

### Declaring Supported Languages

- [SwiftLanguageMode](swift-package-manager/documentation/packagedescription/swiftlanguagemode.md)
- [CXXLanguageStandard](swift-package-manager/documentation/packagedescription/cxxlanguagestandard.md)
- [swiftLanguageModes](swift-package-manager/documentation/packagedescription/package/swiftlanguagemodes.md)
- [cLanguageStandard](swift-package-manager/documentation/packagedescription/package/clanguagestandard.md)
- [cxxLanguageStandard](swift-package-manager/documentation/packagedescription/package/cxxlanguagestandard.md)
- [SwiftVersion](swift-package-manager/documentation/packagedescription/swiftversion.md)
- [swiftLanguageVersions](swift-package-manager/documentation/packagedescription/package/swiftlanguageversions.md)