Trait EnvOverride

pub trait EnvOverride: Sized {
    const DEFAULT_ENV_NAME: &'static str;

    // Required methods
    fn parse_version(value: &str) -> Result<Self, ParseVersionError>;
    fn detect_from_host() -> Result<Option<Self>, DetectVirtualPackageError>;

    // Provided methods
    fn parse_version_opt(
        value: &str,
    ) -> Result<Option<Self>, DetectVirtualPackageError> { ... }
    fn from_env_var_name_or<F>(
        env_var_name: &str,
        fallback: F,
    ) -> Result<Option<Self>, DetectVirtualPackageError>
       where F: FnOnce() -> Result<Option<Self>, DetectVirtualPackageError> { ... }
    fn detect_with_fallback<F>(
        ov: &Override,
        fallback: F,
    ) -> Result<Option<Self>, DetectVirtualPackageError>
       where F: FnOnce() -> Result<Option<Self>, DetectVirtualPackageError> { ... }
    fn detect(
        ov: Option<&Override>,
    ) -> Result<Option<Self>, DetectVirtualPackageError> { ... }
}

Traits for overridable virtual packages Use as Cuda::detect(override)

Required Associated Constants

const DEFAULT_ENV_NAME: &'static str

Default name of the environment variable that overrides the virtual package.

Required Methods

fn parse_version(value: &str) -> Result<Self, ParseVersionError>

Parse env_var_value

fn detect_from_host() -> Result<Option<Self>, DetectVirtualPackageError>

Detect the virtual package for the current system. This method is here so that <Self as EnvOverride>::current always returns the same error type. current may return different types of errors depending on the virtual package. This one always returns DetectVirtualPackageError.

Provided Methods

fn parse_version_opt( value: &str, ) -> Result<Option<Self>, DetectVirtualPackageError>

Helper to convert the output of parse_version and handling empty strings.

fn from_env_var_name_or<F>( env_var_name: &str, fallback: F, ) -> Result<Option<Self>, DetectVirtualPackageError>

where F: FnOnce() -> Result<Option<Self>, DetectVirtualPackageError>,

Read the environment variable and if it exists, try to parse it with EnvOverride::parse_version If the output is:

• None, then the environment variable did not exist,
• Some(Err(None)), then the environment variable exist but was set to zero, so the package should be disabled
• Some(Ok(pkg)), then the override was for the package.

fn detect_with_fallback<F>( ov: &Override, fallback: F, ) -> Result<Option<Self>, DetectVirtualPackageError>

where F: FnOnce() -> Result<Option<Self>, DetectVirtualPackageError>,

Apply the override to the current virtual package. If the override is None then use the fallback

fn detect( ov: Option<&Override>, ) -> Result<Option<Self>, DetectVirtualPackageError>

Shortcut for Self::detect_with_fallback with Self::detect_from_host as fallback

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl EnvOverride for Cuda

const DEFAULT_ENV_NAME: &'static str = "CONDA_OVERRIDE_CUDA"

impl EnvOverride for LibC

const DEFAULT_ENV_NAME: &'static str = "CONDA_OVERRIDE_GLIBC"

impl EnvOverride for Osx

const DEFAULT_ENV_NAME: &'static str = "CONDA_OVERRIDE_OSX"