template_export_semver_check!() { /* proc-macro */ }Expand description
Check semver compatibility, for a crate which exports macros
Causes a compilation error
if and only if the specified version of derive-deftly
is prior to the last relevant change,
compared to the currently-running one.
A relevant change is one which has semver implications for the API of a crate which exports derive-deftly templates.
§When and how to call this
If you export templates, with define_derive_deftly! { export ... },
call this macro too, once in your crate.
Pass it the version of derive-deftly that was current,
when you last read the derive-deftly changelog
and considered breaking changes.
(The argument must be a string literal, containing a 2- or 3-element version number. If the 3rd element is omitted, 0 is used.)
§Guarantee
You can upgrade your derive-deftly version, even across a semver-breaking change to derive-deftly, without making any consequential update to your crate’s own semver.
If a new version of derive-adhoc means your crate’s API has semver-relevant changes, this macro will throw an error. (Of course that will only happen across semver-breaking updates of derive-deftly.)
(Exporting a driver struct for derivation in downstream crates,
#[derive_deftly_adhoc(export)], is not covered by this promise.)
§Example
derive_deftly::template_export_semver_check!("0.13.0");