let lmm_system_free(nullptr) be a noop

[simgrid.git] / include / xbt / system_error.hpp

diff --git a/include/xbt/system_error.hpp b/include/xbt/system_error.hpp
index f2aabe7..f580e75 100644 (file)
--- a/include/xbt/system_error.hpp
+++ b/include/xbt/system_error.hpp
@@ -8,6 +8,9 @@
 
 #include <system_error>
 
+#ifndef SIMGRID_MC_SYSTEM_ERROR_HPP
+#define SIMGRID_MC_SYSTEM_ERROR_HPP
+
 namespace simgrid {
 namespace xbt {
 
@@ -31,3 +34,5 @@ std::system_error errno_error(int errnum, const char* what)
 
 }
 }
+
+#endif