Enum FormatArg 

pub enum FormatArg<'a> {
    Ref(&'a dyn FormatValue),
    Str(&'a str),
}

A format argument - either a trait object reference or a &str slice.

Two variants handle the str unsized coercion gap: &T where T: Sized can coerce to &dyn FormatValue directly, but &str cannot since str is unsized. The Str variant stores the &str directly so that callers can pass string literals without extra & indirection.

Variants

Ref(&'a dyn FormatValue)

A reference to any sized FormatValue.

Str(&'a str)

A string slice (avoids the unsized coercion issue).

Trait Implementations

impl<'a, T: FormatValue> From<&'a T> for FormatArg<'a>

fn from(value: &'a T) -> Self

Converts to this type from the input type.

impl<'a> From<&'a str> for FormatArg<'a>

fn from(value: &'a str) -> Self

Converts to this type from the input type.