From b724ba6eacec78b0caa80a7730752b7158742472 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 2 Apr 2021 22:15:57 +0100
Subject: [PATCH] geometry: Promote PosPromote to a trait

And provide for f64

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 base/geometry.rs | 7 +++++--
 base/prelude.rs  | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/base/geometry.rs b/base/geometry.rs
index df523f79..4040207d 100644
--- a/base/geometry.rs
+++ b/base/geometry.rs
@@ -87,8 +87,11 @@ impl Mean for i32 { fn mean(&self, other: &Self) -> Self {
 
 //---------- Pos ----------
 
-impl PosC<Coord> {
-  pub fn promote(&self) -> PosC<f64> { self.map(|v| v as f64) }
+pub trait PosPromote {
+  fn promote(&self) -> PosC<f64>;
+}
+impl<T> PosPromote for PosC<T> where T: Into<f64> + Copy + Debug {
+  fn promote(&self) -> PosC<f64> { self.map(|v| v.into()) }
 }
 
 #[derive(Error,Debug,Copy,Clone,Serialize,Deserialize)]
diff --git a/base/prelude.rs b/base/prelude.rs
index 092409b0..8348fdfd 100644
--- a/base/prelude.rs
+++ b/base/prelude.rs
@@ -28,7 +28,7 @@ pub use void::Void;
 
 pub use crate::html::*;
 
-pub use crate::geometry::{CoordinateOverflow, PosC};
+pub use crate::geometry::{CoordinateOverflow, PosC, PosPromote};
 pub use crate::{hformat, hformat_as_display, hwrite};
 pub use crate::misc::default;
 pub use crate::misc::display_as_debug;
-- 
2.30.2