Expand description
Returns metadata about a function at runtime.
Currently this includes the TypeId
s of function parameters.
This includes a FnMetadata
struct and FnMetadataExt
trait.
FnMetadataExt
adds the .metadata()
function on functions and closures to
return a FnMetadata
, whose implementation returns function metadata at
runtime.
Usage
Add the following to Cargo.toml
fn_meta = "0.7.3"
fn_meta = { version = "0.7.3", features = ["fn_meta_ext"] }
Code:
use fn_meta::{FnMetaDyn, FnMetadataExt};
fn f1(_: &S0, _: &mut S1, _: &S2) -> () {}
let fn_metadata = f1.metadata();
assert_eq!(
[TypeId::of::<S0>(), TypeId::of::<S2>()],
fn_metadata.borrows().as_slice()
);
assert_eq!([TypeId::of::<S1>()], fn_metadata.borrow_muts().as_slice());
Features
"fn_meta_ext"
:
Enables the FnMeta
and FnMetaExt
traits. FnMetaExt
adds the
.meta()
function on functions and closures to return a Box<dyn FnMeta>
,
which is the dynamic dispatch analog to FnMetadata
.
"high_arg_count"
:
Raises the number of arguments that FnMetaExt
and FnMetadataExt
are
implemented for from 6 to 8.
This is feature gated because compilation time increasing significantly with higher numbers of arguments – as much as from 1.5 seconds for 6 arguments to 8 seconds for 8 arguments.
Structs
Metadata about a function
Traits
Any type that tracks metadata about a function.
Any type that tracks metadata about a function.
Extension to return Box<dyn FnMetaDyn>
for a function.
Extension to return FnMetadata
for a function.