From f4c089776438094e33be29405ffe0a28d3c69f0a Mon Sep 17 00:00:00 2001
From: sebcrozet <developer@crozet.re>
Date: Tue, 21 Apr 2020 10:19:03 +0200
Subject: [PATCH 1/2] Fix compilation of matrix exponential when targetting
 no-std.

---
 src/linalg/exp.rs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/linalg/exp.rs b/src/linalg/exp.rs
index 86bd81a7..df375ac9 100644
--- a/src/linalg/exp.rs
+++ b/src/linalg/exp.rs
@@ -42,7 +42,8 @@ impl<N, D> ExpmPadeHelper<N, D>
 where
     N: RealField,
     D: DimMin<D>,
-    DefaultAllocator: Allocator<N, D, D> + Allocator<(usize, usize), DimMinimum<D, D>>,
+    DefaultAllocator:
+        Allocator<N, D, D> + Allocator<N, D> + Allocator<(usize, usize), DimMinimum<D, D>>,
 {
     fn new(a: MatrixN<N, D>, use_exact_norm: bool) -> Self {
         let (nrows, ncols) = a.data.shape();
@@ -405,15 +406,13 @@ where
     D: Dim,
     DefaultAllocator: Allocator<N, D, D>,
 {
-    let mut col_sums = vec![N::zero(); m.ncols()];
+    let mut max = N::zero();
+
     for i in 0..m.ncols() {
         let col = m.column(i);
-        col.iter().for_each(|v| col_sums[i] += v.abs());
-    }
-    let mut max = col_sums[0];
-    for i in 1..col_sums.len() {
-        max = N::max(max, col_sums[i]);
+        max = max.max(col.iter().fold(N::zero(), |a, b| a + b.abs()));
     }
+
     max
 }
 
@@ -427,7 +426,7 @@ where
     pub fn exp(&self) -> Self {
         // Simple case
         if self.nrows() == 1 {
-            return self.clone().map(|v| v.exp());
+            return self.map(|v| v.exp());
         }
 
         let mut h = ExpmPadeHelper::new(self.clone(), true);

From 6dc739b70b44a0806d3b10bcc5646cea94696a95 Mon Sep 17 00:00:00 2001
From: sebcrozet <developer@crozet.re>
Date: Tue, 21 Apr 2020 10:37:14 +0200
Subject: [PATCH 2/2] Remove unused allocator bound.

---
 src/linalg/exp.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/linalg/exp.rs b/src/linalg/exp.rs
index df375ac9..c11fd757 100644
--- a/src/linalg/exp.rs
+++ b/src/linalg/exp.rs
@@ -42,8 +42,7 @@ impl<N, D> ExpmPadeHelper<N, D>
 where
     N: RealField,
     D: DimMin<D>,
-    DefaultAllocator:
-        Allocator<N, D, D> + Allocator<N, D> + Allocator<(usize, usize), DimMinimum<D, D>>,
+    DefaultAllocator: Allocator<N, D, D> + Allocator<(usize, usize), DimMinimum<D, D>>,
 {
     fn new(a: MatrixN<N, D>, use_exact_norm: bool) -> Self {
         let (nrows, ncols) = a.data.shape();