From 096e156858f9abf0f2314b77cd95ca54d65d0645 Mon Sep 17 00:00:00 2001
From: Nigel Delaney <evolvedmicrobe@users.noreply.github.com>
Date: Tue, 31 May 2022 11:56:27 -0700
Subject: [PATCH] `From -> `TryFrom`

The conversion from LogProb is not guaranteed to succeed, so we use `TryFrom` instead of `From`, as per the Rust docs:

```Note: The From trait must not fail. The From trait is intended for perfect conversions. If the conversion can fail or is not perfect, use TryFrom.```

Note this does change the API.
---
 CHANGELOG.md           |  1 +
 src/stats/probs/mod.rs | 10 ++++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1a65587a..a5d8ffdbc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [0.42.0](https://www.github.com/rust-bio/rust-bio/compare/v0.42.0...v0.41.0) (2022-05-03)
 
+* Change `impl From<LogProb> for NotNan<f64>` to `impl TryFrom<LogProb> for NotNan<f64>` to indicate the conversion can fail.
 * Upgrade `strum` to version `0.24`
 * Upgrade `ordered-float` to `2.0`
 
diff --git a/src/stats/probs/mod.rs b/src/stats/probs/mod.rs
index 8b08161b4..c889b010f 100644
--- a/src/stats/probs/mod.rs
+++ b/src/stats/probs/mod.rs
@@ -10,6 +10,7 @@ pub mod adaptive_integration;
 pub mod cdf;
 pub mod errors;
 
+use std::convert::TryFrom;
 use std::f64;
 use std::iter;
 use std::mem;
@@ -18,7 +19,7 @@ use std::ops::{Add, AddAssign, Div, Mul, Sub, SubAssign};
 use itertools::Itertools;
 use itertools_num::linspace;
 use num_traits::{Float, Zero};
-use ordered_float::NotNan;
+use ordered_float::{FloatIsNan, NotNan};
 
 use crate::utils::FastExp;
 
@@ -401,9 +402,10 @@ impl From<NotNan<f64>> for LogProb {
     }
 }
 
-impl From<LogProb> for NotNan<f64> {
-    fn from(p: LogProb) -> NotNan<f64> {
-        NotNan::new(*p).unwrap()
+impl TryFrom<LogProb> for NotNan<f64> {
+    type Error = FloatIsNan;
+    fn try_from(p: LogProb) -> Result<Self, Self::Error> {
+        NotNan::new(*p)
     }
 }