Add GSL Lite 0.34.0 header-only library

CMakeLists.txt

@@ -119,6 +119,16 @@ add_subdirectory(vendor/xtl)
 add_subdirectory(vendor/xtensor)
 target_link_libraries(xtensor INTERFACE xtl)
 
+#===============================================================================
+# GSL header-only library
+#===============================================================================
+
+add_library(gsl INTERFACE)
+target_include_directories(gsl INTERFACE vendor/gsl/include)
+
+# Make sure contract violations throw exceptions
+target_compile_definitions(gsl INTERFACE GSL_THROW_ON_CONTRACT_VIOLATION)
+
 #===============================================================================
 # RPATH information
 #===============================================================================
@@ -275,7 +285,7 @@ endif()
 # target_link_libraries treats any arguments starting with - but not -l as
 # linker flags. Thus, we can pass both linker flags and libraries together.
 target_link_libraries(libopenmc ${ldflags} ${HDF5_LIBRARIES} ${HDF5_HL_LIBRARIES}
-                      pugixml faddeeva xtensor)
+                      pugixml faddeeva xtensor gsl)
 
 if(dagmc)
   target_compile_definitions(libopenmc PRIVATE DAGMC)

vendor/gsl/include/gsl/gsl

@@ -0,0 +1,27 @@
+//
+// gsl-lite is based on GSL: Guidelines Support Library.
+// For more information see https://github.com/martinmoene/gsl-lite
+//
+// Copyright (c) 2015 Martin Moene
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved. 
+// 
+// This code is licensed under the MIT License (MIT). 
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
+// THE SOFTWARE. 
+
+// mimic MS include hierarchy
+
+#pragma once
+
+#ifndef GSL_GSL_H_INCLUDED
+#define GSL_GSL_H_INCLUDED
+
+#include "gsl-lite.hpp"
+
+#endif // GSL_GSL_H_INCLUDED