From 18b694dad282c543cc2eb786f783f7b94afa3a0d Mon Sep 17 00:00:00 2001
From: Fabian Loeschner <loeschner@cs.rwth-aachen.de>
Date: Mon, 8 Nov 2021 11:10:58 +0100
Subject: [PATCH] Move serialization helper structs into trait impls

---
 nalgebra-sparse/src/csr.rs | 48 +++++++++++++++++---------------------
 1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/nalgebra-sparse/src/csr.rs b/nalgebra-sparse/src/csr.rs
index b98717b8..bc2a3df0 100644
--- a/nalgebra-sparse/src/csr.rs
+++ b/nalgebra-sparse/src/csr.rs
@@ -599,15 +599,6 @@ impl<T> CsrMatrix<T> {
     }
 }
 
-#[cfg_attr(feature = "serde-serialize", derive(Serialize))]
-struct CsrMatrixSerializationHelper<'a, T> {
-    nrows: usize,
-    ncols: usize,
-    row_offsets: &'a [usize],
-    col_indices: &'a [usize],
-    values: &'a [T],
-}
-
 #[cfg(feature = "serde-serialize")]
 impl<T> Serialize for CsrMatrix<T>
 where
@@ -617,7 +608,16 @@ where
     where
         S: Serializer,
     {
-        CsrMatrixSerializationHelper {
+        #[derive(Serialize)]
+        struct CsrMatrixSerializationData<'a, T> {
+            nrows: usize,
+            ncols: usize,
+            row_offsets: &'a [usize],
+            col_indices: &'a [usize],
+            values: &'a [T],
+        }
+
+        CsrMatrixSerializationData {
             nrows: self.nrows(),
             ncols: self.ncols(),
             row_offsets: self.row_offsets(),
@@ -628,15 +628,6 @@ where
     }
 }
 
-#[cfg_attr(feature = "serde-serialize", derive(Deserialize))]
-struct CsrMatrixDeserializationHelper<T> {
-    nrows: usize,
-    ncols: usize,
-    row_offsets: Vec<usize>,
-    col_indices: Vec<usize>,
-    values: Vec<T>,
-}
-
 #[cfg(feature = "serde-serialize")]
 impl<'de, T> Deserialize<'de> for CsrMatrix<T>
 where
@@ -646,14 +637,17 @@ where
     where
         D: Deserializer<'de>,
     {
-        let CsrMatrixDeserializationHelper {
-            nrows,
-            ncols,
-            row_offsets,
-            col_indices,
-            values,
-        } = CsrMatrixDeserializationHelper::deserialize(deserializer)?;
-        CsrMatrix::try_from_csr_data(nrows, ncols, row_offsets, col_indices, values)
+        #[derive(Deserialize)]
+        struct CsrMatrixDeserializationData<T> {
+            nrows: usize,
+            ncols: usize,
+            row_offsets: Vec<usize>,
+            col_indices: Vec<usize>,
+            values: Vec<T>,
+        }
+
+        let de = CsrMatrixDeserializationData::deserialize(deserializer)?;
+        CsrMatrix::try_from_csr_data(de.nrows, de.ncols, de.row_offsets, de.col_indices, de.values)
             .map(|m| m.into())
             // TODO: More specific error
             .map_err(|_e| de::Error::invalid_value(de::Unexpected::Other("invalid CSR matrix"), &"a valid CSR matrix"))