remove special code to support C++11

Don't use the macros
- BOOST_NO_DELETED_FUNCTIONS
- BOOST_NO_EXPLICIT_CONVERSION_OPERATORS
- BOOST_NO_VARIADIC_TEMPLATES
anymore because all compiler support those features now
(https://en.cppreference.com/w/cpp/compiler_support/11).

include/cucumber-cpp/internal/hook/HookRegistrar.hpp

@@ -6,9 +6,7 @@
 #include "../Scenario.hpp"
 #include "../step/StepManager.hpp"
 
-#include <boost/config.hpp>
 #include <memory>
-
 #include <list>
 
 namespace cucumber {
@@ -102,11 +100,7 @@ class CUCUMBER_CPP_EXPORT HookRegistrar {
 
 private:
     // We're a singleton so don't allow instances
-    HookRegistrar()
-#ifndef BOOST_NO_DELETED_FUNCTIONS
-        = delete
-#endif
-        ;
+    HookRegistrar() = delete;
 };
 
 class CUCUMBER_CPP_EXPORT StepCallChain {

include/cucumber-cpp/internal/step/StepManager.hpp

@@ -6,13 +6,8 @@
 #include <stdexcept>
 #include <string>
 #include <vector>
-
-#include <boost/config.hpp>
 #include <memory>
-
-#ifndef BOOST_NO_VARIADIC_TEMPLATES
-    #include <type_traits>
-#endif
+#include <type_traits>
 
 #include <cucumber-cpp/internal/CukeExport.hpp>
 #include "../Table.hpp"
@@ -43,10 +38,7 @@ class CUCUMBER_CPP_EXPORT MatchResult {
     const match_results_type& getResultSet();
     void addMatch(SingleStepMatch match);
 
-#ifndef BOOST_NO_EXPLICIT_CONVERSION_OPERATORS
-    explicit
-#endif
-    operator bool() const;
+    explicit operator bool() const;
 
 private:
     match_results_type resultSet;
@@ -139,13 +131,6 @@ class CUCUMBER_CPP_EXPORT BasicStep {
     const T getInvokeArg();
     const InvokeArgs* getArgs();
 
-#ifdef BOOST_NO_VARIADIC_TEMPLATES
-    // Special case for zero arguments, only thing we bother to support on C++98
-    template<typename Derived, typename R>
-    static R invokeWithArgs(Derived& that, R (Derived::*f)()) {
-        return (that.*f)();
-    }
-#else
     template<typename Derived, typename R, typename... Args, std::size_t... N>
     static R invokeWithIndexedArgs(Derived& that, R (Derived::*f)(Args...), index_sequence<N...>) {
         return (that.*f)(that.pArgs->template getInvokeArg<typename std::decay<Args>::type>(N)...);
@@ -156,7 +141,6 @@ class CUCUMBER_CPP_EXPORT BasicStep {
         that.currentArgIndex = sizeof...(Args);
         return invokeWithIndexedArgs(that, f, index_sequence_for<Args...>{});
     }
-#endif
 
 private:
     // FIXME: awful hack because of Boost::Test
@@ -188,11 +172,7 @@ class CUCUMBER_CPP_EXPORT StepManager {
 
 private:
     // We're a singleton so don't allow instances
-    StepManager()
-#ifndef BOOST_NO_DELETED_FUNCTIONS
-        = delete
-#endif
-        ;
+    StepManager() = delete;
 };
 
 static inline std::string toSourceString(const char* filePath, const int line) {

include/cucumber-cpp/internal/utils/IndexSequence.hpp

@@ -1,11 +1,7 @@
 #ifndef CUKE_INDEXSEQ_HPP_
 #define CUKE_INDEXSEQ_HPP_
 
-#include <boost/config.hpp>
-
-#ifndef BOOST_NO_VARIADIC_TEMPLATES
-
-    #include <utility>
+#include <utility>
 
 namespace cucumber {
 namespace internal {
@@ -16,6 +12,4 @@ using ::std::index_sequence_for;
 }
 }
 
-#endif /* !BOOST_NO_VARIADIC_TEMPLATES */
-
 #endif /* CUKE_INDEXSEQ_HPP_ */

tests/unit/CukeCommandsTest.cpp

@@ -3,8 +3,6 @@
 #include <cucumber-cpp/internal/step/StepMacros.hpp>
 #include "utils/CukeCommandsFixture.hpp"
 
-#include <boost/config.hpp>
-
 using namespace cucumber::internal;
 
 using std::string;
@@ -77,7 +75,6 @@ class CheckAllParametersWithMacro : public CheckAllParameters {
     }
 };
 
-#ifndef BOOST_NO_VARIADIC_TEMPLATES
 class CheckAllParametersWithFuncArgs : public CheckAllParameters {
 public:
     void bodyWithArgs(
@@ -101,7 +98,6 @@ TEST_F(CukeCommandsTest, invokeHandlesParametersWithFuncArgs) {
     // The real test is in TestClass::body()
     runStepBodyTest<CheckAllParametersWithFuncArgs>();
 }
-#endif
 
 TEST_F(CukeCommandsTest, matchesCorrectly) {
     addStepWithMatcher(STATIC_MATCHER);