Feature/ranges part1

cmake/unit_testing.cmake

@@ -28,6 +28,10 @@ endfunction()
 
 add_subdirectory( src/tools/Log/test )
 
+add_subdirectory( src/tools/concepts/Requires/test )
+add_subdirectory( src/tools/concepts/IsRange/test )
+add_subdirectory( src/tools/concepts/IsIterator/test )
+
 add_subdirectory( src/tools/ranges/IteratorView/test )
 add_subdirectory( src/tools/ranges/TransformIterator/test )
 add_subdirectory( src/tools/ranges/make_view/test )

src/tools/concepts.hpp

@@ -0,0 +1,4 @@
+#include "tools/concepts/Require.hpp"
+
+#include "tools/concepts/IsIterator.hpp"
+#include "tools/concepts/IsRange.hpp"

src/tools/concepts/IsIterator.hpp

@@ -0,0 +1,68 @@
+#ifndef NJOY_TOOLS_CONCEPTS_ISITERATOR
+#define NJOY_TOOLS_CONCEPTS_ISITERATOR
+
+// system includes
+#include <type_traits>
+
+// other includes
+
+namespace njoy {
+namespace tools {
+namespace concepts {
+
+  template< typename Iterator >
+  using iterator_category =
+    typename std::iterator_traits< Iterator >::iterator_category;
+
+  // sfinae structures for iterator objects
+
+  template< typename Iterator, typename = void >
+  struct IsIterator : std::false_type {};
+
+  template< typename Iterator >
+  struct IsIterator<
+           Iterator,
+           std::void_t< iterator_category< Iterator > > > : std::true_type {};
+
+  // the following template aliases only work on iterators
+
+  // sfinae structures for input iterator objects
+
+  template< typename Iterator >
+  using IsInputIterator =
+    typename std::is_base_of< std::input_iterator_tag,
+                              iterator_category< Iterator > >;
+
+  // sfinae structures for output iterator objects
+
+  template< typename Iterator >
+  using IsOutputIterator =
+    typename std::is_base_of< std::output_iterator_tag,
+                              iterator_category< Iterator > >;
+
+  // sfinae structures for forward iterator objects
+
+  template< typename Iterator >
+  using IsForwardIterator =
+    typename std::is_base_of< std::forward_iterator_tag,
+                              iterator_category< Iterator > >;
+
+  // sfinae structures for bidirectional iterator objects
+
+  template< typename Iterator >
+  using IsBidirectionalIterator =
+    typename std::is_base_of< std::bidirectional_iterator_tag,
+                              iterator_category< Iterator > >;
+
+  // sfinae structures for random access iterator objects
+
+  template< typename Iterator >
+  using IsRandomAccessIterator =
+    typename std::is_base_of< std::random_access_iterator_tag,
+                              iterator_category< Iterator > >;
+
+} // ranges namespace
+} // tools namespace
+} // njoy namespace
+
+#endif

src/tools/concepts/IsIterator/test/CMakeLists.txt

@@ -0,0 +1 @@
+add_cpp_test( concepts.IsIterator IsIterator.test.cpp )

src/tools/concepts/IsIterator/test/IsIterator.test.cpp

@@ -0,0 +1,177 @@
+// include Catch2
+#include <catch2/catch_test_macros.hpp>
+
+// what we are testing
+#include "tools/concepts/IsIterator.hpp"
+
+// other includes
+#include <iterator>
+#include <forward_list>
+#include <list>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <unordered_set>
+#include <vector>
+
+// convenience typedefs
+using namespace njoy::tools::concepts;
+
+SCENARIO( "IsIterator sfinae objects" ) {
+
+  GIVEN( "different types" ) {
+
+    WHEN( "when applying IsIterator" ) {
+
+      THEN( "true is returned for iterators and false for everything else" ) {
+
+        // non iterator type
+        CHECK( false == IsIterator< int >::value );
+
+        // input iterator types
+        CHECK( true == IsIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( true == IsIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( true == IsIterator< std::forward_list< int >::iterator >::value );
+        CHECK( true == IsIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( true == IsIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( true == IsIterator< std::list< int >::iterator >::value );
+        CHECK( true == IsIterator< std::set< int >::iterator >::value );
+        CHECK( true == IsIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( true == IsIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+
+    WHEN( "when applying IsInputIterator" ) {
+
+      THEN( "true is returned for iterators that conform to input iterators" ) {
+
+        // input iterator type
+        CHECK( true == IsInputIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( false == IsInputIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( true == IsInputIterator< std::forward_list< int >::iterator >::value );
+        CHECK( true == IsInputIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( true == IsInputIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( true == IsInputIterator< std::list< int >::iterator >::value );
+        CHECK( true == IsInputIterator< std::set< int >::iterator >::value );
+        CHECK( true == IsInputIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( true == IsInputIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+
+    WHEN( "when applying IsOutputIterator" ) {
+
+      THEN( "true is returned for iterators that conform to output iterators" ) {
+
+        // input iterator types
+        CHECK( false == IsOutputIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( true == IsOutputIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( false == IsOutputIterator< std::forward_list< int >::iterator >::value );
+        CHECK( false == IsOutputIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( false == IsOutputIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( false == IsOutputIterator< std::list< int >::iterator >::value );
+        CHECK( false == IsOutputIterator< std::set< int >::iterator >::value );
+        CHECK( false == IsOutputIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( false == IsOutputIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+
+    WHEN( "when applying IsForwardIterator" ) {
+
+      THEN( "true is returned for iterators that conform to forward iterators" ) {
+
+        // input iterator types
+        CHECK( false == IsForwardIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( false == IsForwardIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( true == IsForwardIterator< std::forward_list< int >::iterator >::value );
+        CHECK( true == IsForwardIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( true == IsForwardIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( true == IsForwardIterator< std::list< int >::iterator >::value );
+        CHECK( true == IsForwardIterator< std::set< int >::iterator >::value );
+        CHECK( true == IsForwardIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( true == IsForwardIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+
+    WHEN( "when applying IsBidirectionalIterator" ) {
+
+      THEN( "true is returned for iterators that conform to bidirectional iterators" ) {
+
+        // input iterator types
+        CHECK( false == IsBidirectionalIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( false == IsBidirectionalIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( false == IsBidirectionalIterator< std::forward_list< int >::iterator >::value );
+        CHECK( false == IsBidirectionalIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( false == IsBidirectionalIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( true == IsBidirectionalIterator< std::list< int >::iterator >::value );
+        CHECK( true == IsBidirectionalIterator< std::set< int >::iterator >::value );
+        CHECK( true == IsBidirectionalIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( true == IsBidirectionalIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+
+    WHEN( "when applying IsRandomAccessIterator" ) {
+
+      THEN( "true is returned for iterators that conform to random access iterators" ) {
+
+        // input iterator types
+        CHECK( false == IsRandomAccessIterator< std::istream_iterator< int > >::value );
+
+        // output iterator types
+        CHECK( false == IsRandomAccessIterator< std::ostream_iterator< int > >::value );
+
+        // forward iterator types
+        CHECK( false == IsRandomAccessIterator< std::forward_list< int >::iterator >::value );
+        CHECK( false == IsRandomAccessIterator< std::unordered_set< int >::iterator >::value );
+        CHECK( false == IsRandomAccessIterator< std::unordered_map< int, int >::iterator >::value );
+
+        // bidirectional iterator types
+        CHECK( false == IsRandomAccessIterator< std::list< int >::iterator >::value );
+        CHECK( false == IsRandomAccessIterator< std::set< int >::iterator >::value );
+        CHECK( false == IsRandomAccessIterator< std::map< int, int >::iterator >::value );
+
+        // random access iterator types
+        CHECK( true == IsRandomAccessIterator< std::vector< int >::iterator >::value );
+      } // THEN
+    } // WHEN
+  } // GIVEN
+} // SCENARIO

src/tools/concepts/IsRange.hpp

@@ -0,0 +1,26 @@
+#ifndef NJOY_TOOLS_CONCEPTS_ISRANGE
+#define NJOY_TOOLS_CONCEPTS_ISRANGE
+
+// system includes
+#include <type_traits>
+
+// other includes
+
+namespace njoy {
+namespace tools {
+namespace concepts {
+
+  template< typename Range, typename = void >
+  struct IsRange : std::false_type {};
+
+  template< typename Range >
+  struct IsRange< Range,
+                  std::void_t< decltype( std::begin( std::declval< Range >() ) ),
+                               decltype( std::end( std::declval< Range >() ) )
+                             > > : std::true_type {};
+
+} // ranges namespace
+} // tools namespace
+} // njoy namespace
+
+#endif

src/tools/concepts/IsRange/test/CMakeLists.txt

@@ -0,0 +1 @@
+add_cpp_test( concepts.IsRange IsRange.test.cpp )

src/tools/concepts/IsRange/test/IsRange.test.cpp

@@ -0,0 +1,30 @@
+// include Catch2
+#include <catch2/catch_test_macros.hpp>
+
+// what we are testing
+#include "tools/concepts/IsRange.hpp"
+
+// other includes
+#include <vector>
+#include <map>
+
+// convenience typedefs
+using namespace njoy::tools::concepts;
+
+SCENARIO( "IsRange" ) {
+
+  GIVEN( "different types" ) {
+
+    WHEN( "when applying IsRange" ) {
+
+      THEN( "true is returned for ranges and false for everything else" ) {
+
+        CHECK( false == IsRange< int >::value );
+
+        CHECK( true == IsRange< std::vector< int > >::value );
+        CHECK( true == IsRange< const std::vector< int > >::value );
+        CHECK( true == IsRange< std::map< int, int > >::value );
+      } // THEN
+    } // WHEN
+  } // GIVEN
+} // SCENARIO

src/tools/concepts/Requires.hpp

@@ -0,0 +1,20 @@
+#ifndef NJOY_TOOLS_CONCEPTS_REQUIRES
+#define NJOY_TOOLS_CONCEPTS_REQUIRES
+
+// system includes
+#include <type_traits>
+
+// other includes
+
+namespace njoy {
+namespace tools {
+namespace concepts {
+
+  template< bool TrueFalse, template< typename...> class Concept, typename... T >
+  using Requires = typename std::enable_if< Concept< T... >::value == TrueFalse, bool >::type;
+
+} // ranges namespace
+} // tools namespace
+} // njoy namespace
+
+#endif

src/tools/concepts/Requires/test/CMakeLists.txt

@@ -0,0 +1 @@
+add_cpp_test( concepts.Requires Requires.test.cpp )

src/tools/concepts/Requires/test/Requires.test.cpp

@@ -0,0 +1,32 @@
+// include Catch2
+#include <catch2/catch_test_macros.hpp>
+
+// what we are testing
+#include "tools/concepts/Requires.hpp"
+
+// other includes
+
+// convenience typedefs
+using namespace njoy::tools::concepts;
+
+template< typename T, Requires< true, std::is_integral, T > = true >
+bool integer_type( const T& ){ return true; }
+
+template< typename T, Requires< false, std::is_integral, T > = true >
+bool integer_type( const T& ){ return false; }
+
+SCENARIO( "Require" ) {
+
+  GIVEN( "different types" ) {
+
+    WHEN( "when applying Require" ) {
+
+      THEN( "true is returned for integers and false for everything else" ) {
+
+        CHECK( true == integer_type( 1 ) );
+        CHECK( false == integer_type( 1.0 ) );
+        CHECK( false == integer_type( std::vector< int >{} ) );
+      } // THEN
+    } // WHEN
+  } // GIVEN
+} // SCENARIO