From 5fe01237ea325dcdfe2190ad72c5d1d15094b5a7 Mon Sep 17 00:00:00 2001
From: thatdudegrantt <polazzo.grant@gmail.com>
Date: Mon, 18 May 2026 18:44:10 -0400
Subject: [PATCH 1/2] fix: guard size_t template specializations for Win64

On 64-bit Windows, size_t and uint64_t are the same underlying type, causing duplicate explicit template specialization errors when building
the MATLAB wrapper. Guard both wrap<size_t> and unwrap<size_t> with
#if !defined(_WIN64) || defined(__CUDACC__).

this is because gtsam/wrap inherits from the wrap repository.

Successfully locally tested the change in gtsam/wrap/matlab.h, and then migrating to truly make the change. I will be more careful about this in the future.
---
 matlab.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/matlab.h b/matlab.h
index 5c7cf7a..61c786c 100644
--- a/matlab.h
+++ b/matlab.h
@@ -159,13 +159,15 @@ mxArray* wrap<bool>(const bool& value) {
   return result;
 }
 
-// specialization to size_t
+// specialization to size_t but skip Win64 size check & CUDACC check
+#if !defined(_WIN64) || defined(__CUDACC__)
 template<>
 mxArray* wrap<size_t>(const size_t& value) {
   mxArray *result = scalar(mxUINT32OR64_CLASS);
   *(size_t*)mxGetData(result) = value;
   return result;
 }
+#endif
 
 // specialization to int
 template<>
@@ -345,12 +347,14 @@ uint64_t unwrap<uint64_t>(const mxArray* array) {
   return myGetScalar<uint64_t>(array);
 }
 
-// specialization to size_t
+// specialization to size_t but skip Win64 size check (size_t == uint64_t) & CUDACC check
+#if !defined(_WIN64) || defined(__CUDACC__)
 template<>
 size_t unwrap<size_t>(const mxArray* array) {
   checkScalar(array, "unwrap<size_t>");
   return myGetScalar<size_t>(array);
 }
+#endif
 
 // specialization to double
 template<>

From b330797beb5861e81f3c789812250bcb5043186a Mon Sep 17 00:00:00 2001
From: Grant Polazzo <polazzo.grant@gmail.com>
Date: Fri, 22 May 2026 13:54:24 -0400
Subject: [PATCH 2/2] Updating comments on copilot's suggestion

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 matlab.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/matlab.h b/matlab.h
index 61c786c..e7d7df9 100644
--- a/matlab.h
+++ b/matlab.h
@@ -347,7 +347,9 @@ uint64_t unwrap<uint64_t>(const mxArray* array) {
   return myGetScalar<uint64_t>(array);
 }
 
-// specialization to size_t but skip Win64 size check (size_t == uint64_t) & CUDACC check
+// specialization to size_t; omit it on Win64 because size_t is uint64_t there
+// and would duplicate unwrap<uint64_t>. The __CUDACC__ case intentionally
+// bypasses the Win64 guard when compiling with CUDA.
 #if !defined(_WIN64) || defined(__CUDACC__)
 template<>
 size_t unwrap<size_t>(const mxArray* array) {