fixup: dont use static pointer in header

Defining the global pointer static results in the C++ compiler creating a separate pointer for every translation unit, the definition is included in. I'm pretty sure it's not what you want and it's the cause of your problems.

Author: not-matthias

core/CMakeLists.txt

@@ -54,6 +54,7 @@ endif()
 add_library(
     codspeed
     src/codspeed.cpp
+    src/measurement.cpp
     src/walltime.cpp
     src/uri.cpp
     src/workspace.cpp

core/include/measurement.hpp

@@ -15,13 +15,9 @@ extern "C" {
 #include "core.h"
 }
 
-static InstrumentHooks* g_hooks = nullptr;
+extern InstrumentHooks* g_hooks;
 
-inline void measurement_init() {
-  if (!g_hooks) {
-    g_hooks = instrument_hooks_init();
-  }
-}
+void measurement_init();
 
 inline std::string get_version() {
 #ifdef CODSPEED_VERSION

core/src/measurement.cpp

@@ -0,0 +1,9 @@
+#include "measurement.hpp"
+
+InstrumentHooks* g_hooks = nullptr;
+
+void measurement_init() {
+  if (!g_hooks) {
+    g_hooks = instrument_hooks_init();
+  }
+}