src/registry.rs: Add with_prefix to Registry (prometheus#70)

Signed-off-by: Victor Nordam Suadicani <v.n.suadicani@gmail.com>
Signed-off-by: ackintosh <sora.akatsuki@gmail.com>

CHANGELOG.md

@@ -7,15 +7,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [0.17.0] - unreleased
 
 ### Changed
-
 - Updates to Rust 2021 Edition. See [PR 65].
 
-### Removed
+### Added
+- Added a `with_prefix` method to `Registry` to allow initializing a registry with a prefix. See [PR 70].
 
+### Removed
 - Remove `Add` trait implementation for a private type which lead to compile time conflicts with existing `Add` implementations e.g. on `String`. See [PR 69].
 
 [PR 65]: https://github.com/prometheus/client_rust/pull/65
 [PR 69]: https://github.com/prometheus/client_rust/pull/69
+[PR 70]: https://github.com/prometheus/client_rust/pull/70
 
 ## [0.16.0]
 

src/registry.rs

@@ -76,6 +76,14 @@ impl<M> Default for Registry<M> {
 }
 
 impl<M> Registry<M> {
+    /// Creates a new default [`Registry`] with the given prefix.
+    pub fn with_prefix(prefix: impl Into<String>) -> Self {
+        Self {
+            prefix: Some(Prefix(prefix.into())),
+            ..Default::default()
+        }
+    }
+
     /// Register a metric with the [`Registry`].
     ///
     /// Note: In the Open Metrics text exposition format some metric types have