feat: Custom C++ namespace for library (#15)

CMakeLists.txt

@@ -5,17 +5,22 @@
 cmake_minimum_required(VERSION 3.20)
 project(lbstd_version VERSION 0.0.1 LANGUAGES CXX)
 
-option(LBSTD_VERSION_NS_NAME "The enclosing namespace for all classes of std_version" "lbstd")
+set(LBSTD_VERSION_NS "lbstd" CACHE STRING "The enclosing namespace for all classes of std_version")
 option(LBSTD_VERSION_ENABLE_FMTLIB "Enable fmtlib formatters integration" ON)
 option(LBSTD_VERSION_ENABLE_STDFORMAT "Enable std::format integration")
 option(LBSTD_VERSION_ENABLE_TESTS "Enable tests" ON)
 
+if (LBSTD_VERSION_NS STREQUAL "")
+  message(FATAL_ERROR "The enclosing namespace name in variable LBSTD_VERSION_NS must be a non-empty string!")
+endif()
+
 if (LBSTD_VERSION_ENABLE_FMTLIB)
   find_package(fmt REQUIRED)
 endif()
 
 add_library(lbstd_version INTERFACE)
 target_include_directories(lbstd_version INTERFACE "${CMAKE_SOURCE_DIR}/include")
+target_compile_definitions(lbstd_version INTERFACE "LB_STD_VERSION_NS=${LBSTD_VERSION_NS}")
 target_compile_features(lbstd_version INTERFACE cxx_std_20)
 
 if (LBSTD_VERSION_ENABLE_TESTS)

tests/CMakeLists.txt

@@ -2,13 +2,24 @@
 #
 # SPDX-License-Identifier: BSL-1.0 OR BlueOak-1.0.0
 
-enable_testing()
 find_package(doctest REQUIRED)
 
 include(doctest)
 
 add_executable(lbstd_version_tests test.cpp)
 target_link_libraries(lbstd_version_tests doctest::doctest lbstd_version)
 
-doctest_discover_tests(lbstd_version_tests)
+add_executable(lbstd_version_print_ns print_ns.cpp)
+target_link_libraries(lbstd_version_print_ns lbstd_version)
+
+# The manual test for namespace passthrough.
+set(LBSTD_VERSION_CMAKE_NS_PASSTHROUGH "CMake custom library namespace (\"${LBSTD_VERSION_NS}::\") passthrough in C++ code")
+add_test(NAME "${LBSTD_VERSION_CMAKE_NS_PASSTHROUGH}" COMMAND lbstd_version_print_ns)
+set_tests_properties("${LBSTD_VERSION_CMAKE_NS_PASSTHROUGH}" PROPERTIES
+  PASS_REGULAR_EXPRESSION "${LBSTD_VERSION_NS}"
+  LABELS "buildsystem"
+)
+
+# Auto-discoverable doctest unit tests
+doctest_discover_tests(lbstd_version_tests ADD_LABELS ON)
 

tests/print_ns.cpp

@@ -0,0 +1,20 @@
+// SPDX-FileCopyrightText: 2022 leha-bot and contributors
+//
+// SPDX-License-Identifier: BSL-1.0 OR BlueOak-1.0.0
+//
+// This executable is a smoke test for checking the proper namespace customizing via CMake's
+// -DLBSTD_VERSION_NS="namespace_name" configure parameter. The main() function just prints the
+// actual namespace which will be used in CMake's test check.
+#include <iostream>
+
+#include <version/version.hpp>
+
+#define MAKE_STRING(q) #q
+#define UNPACK_MACRO(q) q
+#define MAKE_STRING_FROM_MACRO(q) MAKE_STRING(q)
+
+int main()
+{
+	std::cout << MAKE_STRING_FROM_MACRO(LB_STD_VERSION_NS);
+	return 0;
+}

tests/test.cpp

@@ -8,8 +8,13 @@
 
 #include <type_traits>
 
+#define MAKE_STRING(q) #q
+#define UNPACK_MACRO(q) q
+#define MAKE_STRING_FROM_MACRO(q) MAKE_STRING(q)
+
+
 #define GENERATE_COMPARISON_TEST_CASES(classname, val_less, val_eq, val_greater) \
-TEST_CASE("Comparison tests for " #classname) \
+TEST_CASE("Comparison tests for " MAKE_STRING_FROM_MACRO(classname)) \
 {\
 	classname ver{(val_eq)}, ver_eq{(val_eq)}, ver_less{(val_less)}, ver_greater{(val_greater)}; \
 	SUBCASE("equal") \