many changes, including new spin spaces and groups and cleaning up core library code

1 files changed, 1 insertions, 1 deletions

diff --git a/src/wolff_On.cpp b/src/wolff_On.cpp
index 5458860..cbde498 100644
--- a/src/wolff_On.cpp
+++ b/src/wolff_On.cpp
@@ -206,7 +206,7 @@ int main(int argc, char *argv[]) {
 
   std::function <void(const On_t *)> measurements = measure_function_write_files(measurement_flags, outfiles, other_f);
 
-  std::function <double(vector_R_t)> H;
+  std::function <double(const vector_R_t&)> H;
 
   if (modulated_field) {
     H = std::bind(H_modulated, std::placeholders::_1, order, H_vec[0]);