Support GCC 4.8, using Boost.Regex

.travis.yml

@@ -10,17 +10,24 @@ matrix:
         apt:
           sources: ['ubuntu-toolchain-r-test', 'george-edison55-precise-backports']
           packages: ["g++-5", "cmake-data", "cmake"]
+    - os: linux
+      env:
+        - COMPILER=g++-4.8 USE_BOOST_REGEX=ON
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test', 'george-edison55-precise-backports', 'boost-latest']
+          packages: ["g++-4.8", "cmake-data", "cmake", "libboost-regex1.55-dev"]
 
     - os: linux
-      env: 
+      env:
         - COMPILER=clang++-3.6 STDLIB=libc++
       addons:
         apt:
           sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.6', 'george-edison55-precise-backports']
           packages: ["clang-3.6", "cmake-data", "cmake"]
 
     - os: linux
-      env: 
+      env:
         - COMPILER=clang++-3.7 STDLIB=libc++
       addons:
         apt:
@@ -29,35 +36,41 @@ matrix:
 
     - os: osx
       osx_image: xcode6.4
-      env: 
+      env:
         - COMPILER=clang++ V='Apple LLVM 6.4'
         - COMPILER=clang++ V='Apple LLVM 6.4' WITH_CPP14=true
 
     - os: osx
       osx_image: xcode7
-      env: 
+      env:
         - COMPILER=clang++ V='Apple LLVM 7.0'
         - COMPILER=clang++ V='Apple LLVM 7.0' WITH_CPP14=true
 
 before_install:
   - |
     if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then
-      brew install cmake
+      brew rm --force cmake && brew install cmake
     fi
 
   - CMAKE_CXX_FLAGS+=" -Wall"
 
   - if [[ "${WITH_CPP14}" == "true" ]]; then CMAKE_OPTIONS+=" -DCMAKE_CXX_STANDARD=14"; fi
+  - |
+    if [[ "${USE_BOOST_REGEX}" == "ON" ]]; then
+        CMAKE_OPTIONS+=" -DUSE_BOOST_REGEX=ON"
+        CMAKE_OPTIONS+=" -DBoost_REGEX_LIBRARY_DEBUG=/usr/lib/x86_64-linux-gnu/libboost_regex.so.1.55.0"
+        CMAKE_OPTIONS+=" -DBoost_REGEX_LIBRARY_RELEASE=/usr/lib/x86_64-linux-gnu/libboost_regex.so.1.55.0"
+    fi
   - if [[ "${STDLIB}" == "libc++" ]]; then CMAKE_CXX_FLAGS+=" -stdlib=libc++"; fi
 
-  - sh ${COMPILER} --version || true
+  - ${COMPILER} --version
 
 before_script:
   - rm -rf build/
   - mkdir build
   - cd build
   - cmake -DCMAKE_CXX_COMPILER=${COMPILER} -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS} -DWITH_TESTS=1 -DWITH_EXAMPLE=1 ${CMAKE_OPTIONS} ..
 
-script: 
+script:
   - cmake --build .
   - python run_tests

CMakeLists.txt

@@ -8,6 +8,7 @@ include(GNUInstallDirs)
 #============================================================================
 option(WITH_TESTS "Build tests." OFF)
 option(WITH_EXAMPLE "Build example." OFF)
+option(USE_BOOST_REGEX "Replace std::regex with Boost.Regex" OFF)
 
 #============================================================================
 # Internal compiler options
@@ -52,6 +53,19 @@ if(NOT MSVC)
 	set_target_properties(docopt_s PROPERTIES OUTPUT_NAME docopt)
 endif()
 
+if(USE_BOOST_REGEX)
+	add_definitions("-DDOCTOPT_USE_BOOST_REGEX")
+	# This is needed on Linux, where linking a static library into docopt.so
+	# fails because boost static libs are not compiled with -fPIC
+	set(Boost_USE_STATIC_LIBS OFF)
+    find_package(Boost 1.53 REQUIRED COMPONENTS regex)
+    include_directories(${Boost_INCLUDE_DIRS})
+    target_link_libraries(docopt ${Boost_LIBRARIES})
+	if(WITH_STATIC)
+		target_link_libraries(docopt_s ${Boost_LIBRARIES})
+	endif()
+endif()
+
 #============================================================================
 # Examples
 #============================================================================

README.rst

@@ -42,8 +42,8 @@ and instead can write only the help message--*the way you want it*.
 
     int main(int argc, const char** argv)
     {
-        std::map<std::string, docopt::value> args 
-            = docopt::docopt(USAGE, 
+        std::map<std::string, docopt::value> args
+            = docopt::docopt(USAGE,
                              { argv + 1, argv + argc },
                              true,               // show help if requested
                              "Naval Fate 2.0");  // version string
@@ -78,7 +78,10 @@ to work with docopt:
 - GCC 4.9
 - Visual C++ 2015 RC
 
-Note that GCC-4.8 will not work due to its missing the ``regex`` module. 
+GCC-4.8 can work, but the std::regex module needs to be replaced with ``Boost.Regex``.
+In that case, you will need to define ``DOCTOPT_USE_BOOST_REGEX`` when compiling
+docopt, and link your code with the appropriated Boost libraries. A relativley
+recent version of Boost is needed: 1.55 works, but 1.46 does not for example.
 
 This port is licensed under the MIT license, just like the original module.
 However, we are also dual-licensing this code under the Boost License, version 1.0,
@@ -92,8 +95,8 @@ The differences from the Python port are:
 * a ``docopt::value`` type to hold the various value types that can be parsed.
   We considered using boost::variant, but it seems better to have no external
   dependencies (beyond a good STL).
-* because C++ is statically-typed and Python is not, we had to make some 
-  changes to the interfaces of the internal parse tree types. 
+* because C++ is statically-typed and Python is not, we had to make some
+  changes to the interfaces of the internal parse tree types.
 * because ``std::regex`` does not have an equivalent to Python's regex.split,
   some of the regex's had to be restructured and additional loops used.
 
@@ -126,7 +129,7 @@ API
 - ``argv`` is a vector of strings representing the args passed. Although
   main usually takes a ``(int argc, const char** argv)`` pair, you can
   pass the value ``{argv+1, argv+argc}`` to generate the vector automatically.
-  (Note we skip the argv[0] argument!) Alternatively you can supply a list of 
+  (Note we skip the argv[0] argument!) Alternatively you can supply a list of
   strings like ``{ "--verbose", "-o", "hai.txt" }``.
 
 - ``help``, by default ``true``, specifies whether the parser should
@@ -155,8 +158,8 @@ API
   compatibility with POSIX, or if you want to dispatch your arguments
   to other programs.
 
-The **return** value is a ``map<string, docopt::value>`` with options, 
-arguments and commands as keys, spelled exactly like in your help message.  
+The **return** value is a ``map<string, docopt::value>`` with options,
+arguments and commands as keys, spelled exactly like in your help message.
 Long versions of options are given priority. For example, if you invoke the
 top example as::
 
@@ -372,7 +375,7 @@ We have an extensive list of `examples
 every aspect of functionality of **docopt**.  Try them out, read the
 source if in doubt.
 
-There are also very intersting applications and ideas at that page. 
+There are also very intersting applications and ideas at that page.
 Check out the sister project for more information!
 
 Subparsers, multi-level help and *huge* applications (like git)
@@ -397,7 +400,7 @@ a C++ test case runner (run_testcase.cpp)::
 
   $ clang++ --std=c++11 --stdlib=libc++ docopt.cpp run_testcase.cpp -o run_testcase
   $ python run_tests.py
-  PASS (175) 
+  PASS (175)
 
 You can also compile the example shown at the start (included as example.cpp)::
 
@@ -424,10 +427,10 @@ You can also compile the example shown at the start (included as example.cpp)::
 Development
 ---------------------------------------------------
 
-Comments and suggestions are *very* welcome! If you find issues, please 
+Comments and suggestions are *very* welcome! If you find issues, please
 file them and help improve our code!
 
-Please note, however, that we have tried to stay true to the original 
+Please note, however, that we have tried to stay true to the original
 Python code. If you have any major patches, structural changes, or new features,
 we might want to first negotiate these changes into the Python code first.
 However, bring it up! Let's hear it!
@@ -439,4 +442,3 @@ Changelog
 first release with stable API will be 1.0.0 (soon).
 
 - 0.6.1 The initial C++ port of docopt.py
-

docopt.cpp

@@ -17,7 +17,6 @@
 #include <unordered_map>
 #include <map>
 #include <string>
-#include <regex>
 #include <iostream>
 #include <cassert>
 #include <cstddef>
@@ -522,31 +521,23 @@ static PatternList parse_argv(Tokens tokens, std::vector<Option>& options, bool
 	return ret;
 }
 
-static std::vector<Option> parse_defaults(std::string const& doc) {
-	// This pattern is a bit more complex than the python docopt one due to lack of
-	// re.split. Effectively, it grabs any line with leading whitespace and then a
-	// hyphen; it stops grabbing when it hits another line that also looks like that.
-	static std::regex const pattern {
+std::vector<Option> parse_defaults(std::string const& doc) {
+	// This pattern is a delimiter by which we split the options.
+	// The delimiter is a new line followed by a whitespace(s) followed by one or two hyphens.
+	static std::regex const re_delimiter{
 		"(?:^|\\n)[ \\t]*"  // a new line with leading whitespace
-		"(-(.|\\n)*?)"      // a hyphen, and then grab everything it can...
-		"(?=\\n[ \\t]*-|$)" //  .. until it hits another new line with space and a hyphen
+		"(?=-{1,2})"        // [split happens here] (positive lookahead) ... and followed by one or two hyphes
 	};
 
 	std::vector<Option> defaults;
+	for (auto s : parse_section("options:", doc)) {
+		s.erase(s.begin(), s.begin() + s.find(':') + 1); // get rid of "options:"
 
-	for(auto s : parse_section("options:", doc)) {
-		s.erase(s.begin(), s.begin()+static_cast<std::ptrdiff_t>(s.find(':'))+1); // get rid of "options:"
-
-		std::for_each(std::sregex_iterator{ s.begin(), s.end(), pattern },
-			      std::sregex_iterator{},
-			      [&](std::smatch const& m)
-		{
-			std::string opt = m[1].str();
-
+		for (const auto& opt : regex_split(s, re_delimiter)) {
 			if (starts_with(opt, "-")) {
 				defaults.emplace_back(Option::parse(opt));
 			}
-		});
+		}
 	}
 
 	return defaults;