Merge pull request yhirose#72 from romeoxbm/master

Replace peg::any with std::any

Author: yhirose

CMakeLists.txt

@@ -1,37 +1,26 @@
-cmake_minimum_required(VERSION 2.8)
-
-# Check if a supported compiler is used and add c++11 flag:
-if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
-    message(FATAL_ERROR "Need at least gcc 4.9 to compile.")
-  endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-elseif(MSVC)
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19)
-    message(FATAL_ERROR "Visual Studio 2015 or newer is required.")
-  endif()
-elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0)
-    message(FATAL_ERROR "Need at least AppleClang 7.0 to compile.")
+cmake_minimum_required(VERSION 3.1.0)
+project("cpp-peglib")
+
+# Check if a supported compiler is used to setup the C++ standard to use:
+get_property(known_features GLOBAL PROPERTY CMAKE_CXX_KNOWN_FEATURES)
+list(FIND known_features "cxx_std_17" found)
+if(NOT ${found} EQUAL -1)
+  # C++17 standard is supported
+  set(CMAKE_CXX_STANDARD 17)
+else()
+  # Check for C++11 standard support
+  list(FIND known_features "cxx_std_11" found)
+  if(NOT ${found} EQUAL -1)
+    # C++11 standard is supported
+    set(CMAKE_CXX_STANDARD 11)
   endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.4)
-    message(FATAL_ERROR "Clang below version 3.4 will most likely not work. Please upgrade your compiler.")
-  endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-else() # no GNU, no MSVC, no Clang
-  message(WARNING "You are using an unsupported compiler. Compilation has only been tested with MSVC, GCC and Clang.")
+endif()
 
-  include(CheckCXXCompilerFlag)
-  check_cxx_compiler_flag(-std=c++11 HAS_CXX11_FLAG)
-  if(HAS_CXX11_FLAG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-  else()
-    message(FATAL_ERROR "Your compiler doesn't support the '-std=c++11' flag.")
-  endif()
+if(${found} EQUAL -1)
+  message(FATAL_ERROR "Your compiler is not supported.")
 endif()
 
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
     OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")

README.md

@@ -110,7 +110,14 @@ There are four semantic actions available:
 
 `any& dt` is a 'read-write' context data which can be used for whatever purposes. The initial context data is set in `peg::parser::parse` method.
 
-`peg::any` is a simpler implementatin of [boost::any](http://www.boost.org/doc/libs/1_57_0/doc/html/any.html). It can wrap arbitrary data type.
+`peg::any` is a simpler implementatin of [boost::any](http://www.boost.org/doc/libs/1_57_0/doc/html/any.html). It can wrap arbitrary data type.  
+If the compiler in use supports C++17, by default `peg::any` is defined as an alias to `std::any`.  
+To force using the simpler `any` implementation that comes with `cpp-peglib`, define `PEGLIB_USE_STD_ANY` as 0 before including `peglib.h`:  
+```cpp
+#define PEGLIB_USE_STD_ANY 0
+#include <peglib.h>
+[...]
+```
 
 A semantic action can return a value of arbitrary data type, which will be wrapped by `peg::any`. If a user returns nothing in a semantic action, the first semantic value in the `const SemanticValues& sv` argument will be returned. (Yacc parser has the same behavior.)
 

example/calc.cc

@@ -10,20 +10,19 @@
 #include <cstdlib>
 
 using namespace peg;
-using namespace std;
 
 int main(int argc, const char** argv)
 {
-    if (argc < 2 || string("--help") == argv[1]) {
-        cout << "usage: calc [formula]" << endl;
+    if (argc < 2 || std::string("--help") == argv[1]) {
+        std::cout << "usage: calc [formula]" << std::endl;
         return 1;
     }
 
     auto reduce = [](const SemanticValues& sv) -> long {
-        auto result = sv[0].get<long>();
+        auto result = any_cast<long>(sv[0]);
         for (auto i = 1u; i < sv.size(); i += 2) {
-            auto num = sv[i + 1].get<long>();
-            auto ope = sv[i].get<char>();
+            auto num = any_cast<long>(sv[i + 1]);
+            auto ope = any_cast<char>(sv[i]);
             switch (ope) {
                 case '+': result += num; break;
                 case '-': result -= num; break;
@@ -53,11 +52,11 @@ int main(int argc, const char** argv)
     auto expr = argv[1];
     long val = 0;
     if (parser.parse(expr, val)) {
-        cout << expr << " = " << val << endl;
+        std::cout << expr << " = " << val << std::endl;
         return 0;
     }
 
-    cout << "syntax error..." << endl;
+    std::cout << "syntax error..." << std::endl;
 
     return -1;
 }

example/calc2.cc

@@ -10,7 +10,6 @@
 #include <cstdlib>
 
 using namespace peg;
-using namespace std;
 
 //
 //  PEG syntax:
@@ -24,16 +23,16 @@ using namespace std;
 //
 int main(int argc, const char** argv)
 {
-    if (argc < 2 || string("--help") == argv[1]) {
-        cout << "usage: calc [formula]" << endl;
+    if (argc < 2 || std::string("--help") == argv[1]) {
+        std::cout << "usage: calc [formula]" << std::endl;
         return 1;
     }
 
     auto reduce = [](const SemanticValues& sv) -> long {
-        auto result = sv[0].get<long>();
+        auto result = any_cast<long>(sv[0]);
         for (auto i = 1u; i < sv.size(); i += 2) {
-            auto num = sv[i + 1].get<long>();
-            auto ope = sv[i].get<char>();
+            auto num = any_cast<long>(sv[i + 1]);
+            auto ope = any_cast<char>(sv[i]);
             switch (ope) {
                 case '+': result += num; break;
                 case '-': result -= num; break;
@@ -56,7 +55,7 @@ int main(int argc, const char** argv)
     auto expr = argv[1];
     long val = 0;
     if (EXPRESSION.parse_and_get_value(expr, val).ret) {
-        cout << expr << " = " << val << endl;
+        std::cout << expr << " = " << val << std::endl;
         return 0;
     }
 

example/calc3.cc

@@ -10,16 +10,15 @@
 #include <cstdlib>
 
 using namespace peg;
-using namespace std;
 
 int main(int argc, const char** argv)
 {
-    if (argc < 2 || string("--help") == argv[1]) {
-        cout << "usage: calc3 [formula]" << endl;
+    if (argc < 2 || std::string("--help") == argv[1]) {
+        std::cout << "usage: calc3 [formula]" << std::endl;
         return 1;
     }
 
-    function<long (const Ast&)> eval = [&](const Ast& ast) {
+    std::function<long (const Ast&)> eval = [&](const Ast& ast) {
         if (ast.name == "NUMBER") {
             return stol(ast.token);
         } else {
@@ -54,15 +53,15 @@ int main(int argc, const char** argv)
     parser.enable_ast();
 
     auto expr = argv[1];
-    shared_ptr<Ast> ast;
+    std::shared_ptr<Ast> ast;
     if (parser.parse(expr, ast)) {
         ast = AstOptimizer(true).optimize(ast);
-        cout << ast_to_s(ast);
-        cout << expr << " = " << eval(*ast) << endl;
+        std::cout << ast_to_s(ast);
+        std::cout << expr << " = " << eval(*ast) << std::endl;
         return 0;
     }
 
-    cout << "syntax error..." << endl;
+    std::cout << "syntax error..." << std::endl;
 
     return -1;
 }