From 35d679ad8ccaa5d6f7f8465a9b80b1dc4019a6ea Mon Sep 17 00:00:00 2001
From: Dennis Klein <d.klein@gsi.de>
Date: Fri, 19 Aug 2022 13:04:45 +0200
Subject: [PATCH] build: Add feature flag `FAIRMQ_HAS_STD_PMR`

Currently Clang (libc++) does not implement <memory_resource>.
---
 cmake/FairMQProjectSettings.cmake | 9 +++++++++
 fairmq/CMakeLists.txt             | 5 ++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/cmake/FairMQProjectSettings.cmake b/cmake/FairMQProjectSettings.cmake
index b3621c8d..c860c6da 100644
--- a/cmake/FairMQProjectSettings.cmake
+++ b/cmake/FairMQProjectSettings.cmake
@@ -174,3 +174,12 @@ if(    CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
 else()
   set(FAIRMQ_HAS_STD_FILESYSTEM 1)
 endif()
+
+if(NOT DEFINED FAIRMQ_HAS_STD_PMR)
+  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    # Clang (to be more precise: libc++) currently does not implement <memory_resource>
+    set(FAIRMQ_HAS_STD_PMR 0)
+  else()
+    set(FAIRMQ_HAS_STD_PMR 1)
+  endif()
+endif()
diff --git a/fairmq/CMakeLists.txt b/fairmq/CMakeLists.txt
index ec8119b7..090267d2 100644
--- a/fairmq/CMakeLists.txt
+++ b/fairmq/CMakeLists.txt
@@ -187,7 +187,10 @@ if(BUILD_FAIRMQ)
   if(BUILD_OFI_TRANSPORT)
     target_compile_definitions(${target} PRIVATE BUILD_OFI_TRANSPORT)
   endif()
-  target_compile_definitions(${target} PUBLIC FAIRMQ_HAS_STD_FILESYSTEM=${FAIRMQ_HAS_STD_FILESYSTEM})
+  target_compile_definitions(${target} PUBLIC
+    FAIRMQ_HAS_STD_FILESYSTEM=${FAIRMQ_HAS_STD_FILESYSTEM}
+    FAIRMQ_HAS_STD_PMR=${FAIRMQ_HAS_STD_PMR}
+  )
 
 
   #######################