# tracing_core::metadata - Rust
API documentation for the Rust `metadata` macro in crate `tracing_core`.
Keywords: rust, rustlang, rust-lang, metadata

# Macro tracing_core::metadata [−] [src]

    macro_rules! metadata {
        (
            name: $name:expr,
            target: $target:expr,
            level: $level:expr,
            fields: $fields:expr,
            callsite: $callsite:expr,
            kind: $kind:expr
        ) => { ... };
        (
            name: $name:expr,
            target: $target:expr,
            level: $level:expr,
            fields: $fields:expr,
            callsite: $callsite:expr,
            kind: $kind:expr,
        ) => { ... };
    }

Statically constructs new span metadata.

/// For example:

    use tracing_core::metadata::{Kind, Level, Metadata};
    static FOO_CALLSITE: MyCallsite = MyCallsite {
        // ...
    };

    static FOO_METADATA: Metadata = metadata!{
        name: "foo",
        target: module_path!(),
        level: Level::DEBUG,
        fields: &["bar", "baz"],
        callsite: &FOO_CALLSITE,
        kind: Kind::SPAN,
    };