add single_header CMake target

.gitignore

@@ -21,3 +21,6 @@ benchmarks/files/numbers/*.json
 cmake-build-debug
 
 test/test-*
+amalgamate
+single_include
+third_party/Amalgamate

CMakeLists.txt

@@ -7,6 +7,12 @@ cmake_minimum_required(VERSION 3.0.0)
 project(nlohmann_json VERSION 3.0.1 LANGUAGES CXX)
 
 ##
+## INCLUDE
+##
+##
+include(ExternalProject)
+
+##
 ## OPTIONS
 ##
 option(JSON_BuildTests "Build the unit tests when BUILD_TESTING is enabled." ON)
@@ -15,7 +21,7 @@ option(JSON_BuildTests "Build the unit tests when BUILD_TESTING is enabled." ON)
 ## CONFIGURATION
 ##
 set(NLOHMANN_JSON_TARGET_NAME               ${PROJECT_NAME})
-set(NLOHMANN_JSON_SOURCE_DIR                "src/")
+set(NLOHMANN_JSON_SOURCE_DIR                "src")
 set(NLOHMANN_JSON_CONFIG_INSTALL_DIR        "lib/cmake/${PROJECT_NAME}")
 set(NLOHMANN_JSON_INCLUDE_INSTALL_DIR       "include")
 set(NLOHMANN_JSON_HEADER_INSTALL_DIR        "${NLOHMANN_JSON_INCLUDE_INSTALL_DIR}/nlohmann")
@@ -62,6 +68,19 @@ if(BUILD_TESTING AND JSON_BuildTests)
     add_subdirectory(test)
 endif()
 
+ExternalProject_Add(amalgamate
+  GIT_REPOSITORY "https://github.com/theodelrieu/Amalgamate"
+  CMAKE_ARGS "-DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}"
+)
+
+# There is no way to tell amalgamate to force-write the output file even if it already exists...
+add_custom_target(single_header ALL rm -f "${CMAKE_SOURCE_DIR}/single_header/json.hpp"
+  COMMENT "Amalgamating json.hpp..."
+  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/${NLOHMANN_JSON_SOURCE_DIR}
+  DEPENDS amalgamate
+  COMMAND "${CMAKE_BINARY_DIR}/bin/amalgamate" -w '*.hpp' -i . json.hpp "${CMAKE_SOURCE_DIR}/single_header/json.hpp"
+)
+
 ##
 ## INSTALL
 ## install header files, generate and install cmake config files for find_package()

Makefile

 .PHONY: pretty clean ChangeLog.md
 
-SRCDIR = src
-SRCS = ${SRCDIR}/json.hpp \
-			 ${SRCDIR}/json_fwd.hpp \
-			 ${SRCDIR}/detail/macro_scope.hpp \
-			 ${SRCDIR}/detail/macro_unscope.hpp \
-			 ${SRCDIR}/detail/meta.hpp \
-			 ${SRCDIR}/detail/exceptions.hpp \
-			 ${SRCDIR}/detail/value_t.hpp \
-			 ${SRCDIR}/detail/conversions/from_json.hpp \
-			 ${SRCDIR}/detail/conversions/to_json.hpp \
-			 ${SRCDIR}/detail/parsing/input_adapters.hpp \
-			 ${SRCDIR}/detail/parsing/lexer.hpp \
-			 ${SRCDIR}/detail/parsing/parser.hpp \
-			 ${SRCDIR}/detail/iterators/primitive_iterator.hpp \
-			 ${SRCDIR}/detail/iterators/internal_iterator.hpp \
-			 ${SRCDIR}/detail/iterators/iter_impl.hpp \
-			 ${SRCDIR}/detail/iterators/iteration_proxy.hpp \
-			 ${SRCDIR}/detail/iterators/json_reverse_iterator.hpp \
-			 ${SRCDIR}/detail/parsing/output_adapters.hpp \
-			 ${SRCDIR}/detail/parsing/binary_reader.hpp \
-			 ${SRCDIR}/detail/parsing/binary_writer.hpp \
-			 ${SRCDIR}/detail/serializer.hpp \
-			 ${SRCDIR}/detail/json_ref.hpp \
-			 ${SRCDIR}/adl_serializer.hpp
+SRCDIR = ./src
+SRCS = $(SRCDIR)/json.hpp \
+			 $(SRCDIR)/json_fwd.hpp \
+			 $(SRCDIR)/detail/macro_scope.hpp \
+			 $(SRCDIR)/detail/macro_unscope.hpp \
+			 $(SRCDIR)/detail/meta.hpp \
+			 $(SRCDIR)/detail/exceptions.hpp \
+			 $(SRCDIR)/detail/value_t.hpp \
+			 $(SRCDIR)/detail/conversions/from_json.hpp \
+			 $(SRCDIR)/detail/conversions/to_json.hpp \
+			 $(SRCDIR)/detail/parsing/input_adapters.hpp \
+			 $(SRCDIR)/detail/parsing/lexer.hpp \
+			 $(SRCDIR)/detail/parsing/parser.hpp \
+			 $(SRCDIR)/detail/iterators/primitive_iterator.hpp \
+			 $(SRCDIR)/detail/iterators/internal_iterator.hpp \
+			 $(SRCDIR)/detail/iterators/iter_impl.hpp \
+			 $(SRCDIR)/detail/iterators/iteration_proxy.hpp \
+			 $(SRCDIR)/detail/iterators/json_reverse_iterator.hpp \
+			 $(SRCDIR)/detail/parsing/output_adapters.hpp \
+			 $(SRCDIR)/detail/parsing/binary_reader.hpp \
+			 $(SRCDIR)/detail/parsing/binary_writer.hpp \
+			 $(SRCDIR)/detail/serializer.hpp \
+			 $(SRCDIR)/detail/json_ref.hpp \
+			 $(SRCDIR)/adl_serializer.hpp
+
+UNAME = $(shell uname)
+CXX=clang++
 
 # main target
 all:
@@ -42,7 +45,6 @@ all:
 	@echo "pedantic_gcc - run GCC with maximal warning flags"
 	@echo "pretty - beautify code with Artistic Style"
 
-
 ##########################################################################
 # unit tests
 ##########################################################################
@@ -247,6 +249,7 @@ pretty:
 	   $(SRCS) test/src/*.cpp \
 	   benchmarks/src/benchmarks.cpp doc/examples/*.cpp
 
+
 ##########################################################################
 # changelog
 ##########################################################################

test/Makefile

@@ -77,7 +77,7 @@ test-%: src/unit-%.o src/unit.o ../src/json.hpp thirdparty/catch/catch.hpp
 
 TEST_PATTERN ?= "*"
 TEST_PREFIX = ""
-check: $(TESTCASES)
+check: $(OBJECTS) $(TESTCASES)
 	@cd .. ; for testcase in $(TESTCASES); do echo "Executing $$testcase..."; $(TEST_PREFIX)test/$$testcase $(TEST_PATTERN) || exit 1; done