error: explicit specialization in non-namespace scope

[dromer]

Ran into this using gcc 14.2.0:

/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1055:18: error: explicit specialization in non-namespace scope ‘struct signalsmith::linear::LinearImpl<<anonymous> >’
 1055 |         template<>
      |                  ^
/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1056:14: error: template-id ‘reserve<float>’ in declaration of primary template
 1056 |         void reserve<float>(size_t size) {
      |              ^~~~~~~~~~~~~~
/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1059:18: error: explicit specialization in non-namespace scope ‘struct signalsmith::linear::LinearImpl<<anonymous> >’
 1059 |         template<>
      |                  ^
/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1060:14: error: template-id ‘reserve<double>’ in declaration of primary template
 1060 |         void reserve<double>(size_t size) {
      |              ^~~~~~~~~~~~~~~
/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1060:14: error: ‘void signalsmith::linear::LinearImpl<<anonymous> >::reserve(size_t)’ cannot be overloaded with ‘void signalsmith::linear::LinearImpl<<anonymous> >::reserve(size_t)’
/home/dreamer/Sources/_projects/_pgm/PGM-App/build/_deps/signalsmith-linear-src/include/signalsmith-linear/../../linear.h:1056:14: note: previous declaration ‘void signalsmith::linear::LinearImpl<<anonymous> >::reserve(size_t)’
 1056 |         void reserve<float>(size_t size) {
      |              ^~~~~~~~~~~~~~

Quick fix was this:

        template<typename V>
-       void reserve(size_t) {}
-       // Makes sure we don't allocate
-       template<>
-       void reserve<float>(size_t size) {
-               cached.reserveFloats(size);
-       }
-       template<>
-       void reserve<double>(size_t size) {
-               cached.reserveDoubles(size);
+       void reserve(size_t size) {
+               // Makes sure we don't allocate
+               if constexpr (std::is_same<V, float>::value) {
+                       cached.reserveFloats(size);
+               } else if constexpr (std::is_same<V, double>::value) {
+                       cached.reserveDoubles(size);
+               }
        }