Update CMakeLists.txt

Author: perazz

test/hash_functions/CMakeLists.txt

@@ -14,13 +14,22 @@ target_sources(
   waterhash.c
   generate_hash_arrays.cpp
 )
+
 if(CMAKE_Fortran_COMPILER_ID MATCHES "^Intel")
+
+  # Set the C++ standard to prevent icpc breakage
+  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD_REQUIRED ON)
+  set(CMAKE_CXX_EXTENSIONS OFF)
+
   set_target_properties(test_hash_functions PROPERTIES LINKER_LANGUAGE Fortran)
 endif()
+
 if(CMAKE_Fortran_COMPILER_ID STREQUAL GNU AND CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 10.0)
   target_compile_options(
     test_hash_functions
     PRIVATE
     $<$<COMPILE_LANGUAGE:Fortran>:-fno-range-check>
-   )
+  )
 endif()
+