adding some CMake help

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.12)
 
 project(mlspp
-  VERSION 3
+  VERSION 3.0.1
   LANGUAGES CXX
 )
 
@@ -14,11 +14,26 @@ option(SANITIZERS "Enable sanitizers" OFF)
 ###
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
-set(MLS_NAMESPACE mls_v${PROJECT_VERSION})
+###
+### Determine Namespacing
+### Using the version number of the project to create the namespace.
+### 3.0.0 -> v3
+### 3.1.0 -> v3_1
+### 3.1.1 -> v3_1_1
+###
+set(MLS_NAMESPACE_VERSION "v${PROJECT_VERSION}")
+string(REPLACE "." "_" MLS_NAMESPACE_VERSION ${MLS_NAMESPACE_VERSION})
+string(REGEX REPLACE "_0$" "" MLS_NAMESPACE_VERSION ${MLS_NAMESPACE_VERSION})
+string(REGEX REPLACE "_0$" "" MLS_NAMESPACE_VERSION ${MLS_NAMESPACE_VERSION})
+set(MLS_CPP_NAMESPACE "mls${MLS_NAMESPACE_VERSION}")
+set(MLS_CMAKE_NAMESPACE "MLSPP${MLS_NAMESPACE_VERSION}")
+set(MLS_CMAKE_CONFIG_NAMESPACE "mlspp${MLS_NAMESPACE_VERSION}")
 configure_file("${CMAKE_CURRENT_SOURCE_DIR}/include/namespace.h.in"
   "${CMAKE_BINARY_DIR}/include/namespace.h" @ONLY)
 include_directories("${CMAKE_BINARY_DIR}/include")
-message(STATUS "Using namespace: ${MLS_NAMESPACE}")
+message(STATUS "MLS_CPP_NAMESPACE: ${MLS_CPP_NAMESPACE}")
+message(STATUS "MLS_CMAKE_NAMESPACE: ${MLS_CMAKE_NAMESPACE}")
+message(STATUS "MLS_CMAKE_CONFIG_NAMESPACE: ${MLS_CMAKE_CONFIG_NAMESPACE}")
 
 include(CheckCXXCompilerFlag)
 include(CMakePackageConfigHelpers)
@@ -115,7 +130,7 @@ target_link_libraries(${LIB_NAME} bytes tls_syntax hpke)
 target_include_directories(${LIB_NAME}
   PUBLIC
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
-    $<INSTALL_INTERFACE:include/${PROJECT_NAME}>
+    $<INSTALL_INTERFACE:include/${MLS_CPP_NAMESPACE}>
   PRIVATE
     ${OPENSSL_INCLUDE_DIR}
 )
@@ -132,17 +147,17 @@ endif()
 ###
 set(CMAKE_EXPORT_PACKAGE_REGISTRY ON)
 export(EXPORT mlspp-targets 
-       NAMESPACE MLSPP::
-       FILE ${CMAKE_CURRENT_BINARY_DIR}/mlspp-targets.cmake)
-export(PACKAGE MLSPP)
+       NAMESPACE ${MLS_CMAKE_NAMESPACE}::
+       FILE ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-targets.cmake)
+export(PACKAGE ${MLS_CMAKE_NAMESPACE})
 
 configure_package_config_file(cmake/config.cmake.in
-  ${CMAKE_CURRENT_BINARY_DIR}/mlspp-config.cmake
+  ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-config.cmake
   INSTALL_DESTINATION ${CMAKE_INSTALL_DATADIR}/mlspp
   NO_SET_AND_CHECK_MACRO)
 
 write_basic_package_version_file(
-  ${CMAKE_CURRENT_BINARY_DIR}/mlspp-config-version.cmake
+  ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-config-version.cmake
   VERSION ${PROJECT_VERSION}
   COMPATIBILITY SameMajorVersion)
 
@@ -156,13 +171,13 @@ install(
   DIRECTORY
     include/
   DESTINATION
-    ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME})
+    ${CMAKE_INSTALL_INCLUDEDIR}/${MLS_CPP_NAMESPACE})
 
 install(
   FILES
-    ${CMAKE_CURRENT_BINARY_DIR}/mlspp-config.cmake
-    ${CMAKE_CURRENT_BINARY_DIR}/mlspp-config-version.cmake
-    ${CMAKE_CURRENT_BINARY_DIR}/mlspp-targets.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-config.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-config-version.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/${MLS_CMAKE_CONFIG_NAMESPACE}-targets.cmake
   DESTINATION
-    ${CMAKE_INSTALL_DATADIR}/mlspp)
+    ${CMAKE_INSTALL_DATADIR}/${MLS_CPP_NAMESPACE})
 

include/namespace.h.in

@@ -1,4 +1,4 @@
 #pragma once
 
 // Configurable top-level MLS namespace
-#define MLS_NAMESPACE @MLS_NAMESPACE@
+#define MLS_NAMESPACE @MLS_CPP_NAMESPACE@