Merge pull request #311

Implemented #260.

3 files changed, 39 insertions, 29 deletions

diff --git a/include/multi_span.h b/include/multi_span.h
index a8a1af2..c883fb0 100644
--- a/include/multi_span.h
+++ b/include/multi_span.h
@@ -1053,18 +1053,28 @@ template <typename Span>
 class general_span_iterator;
 
 template <std::ptrdiff_t DimSize = dynamic_range>
-struct dim
+struct dim_t
 {
     static const std::ptrdiff_t value = DimSize;
 };
 template <>
-struct dim<dynamic_range>
+struct dim_t<dynamic_range>
 {
     static const std::ptrdiff_t value = dynamic_range;
     const std::ptrdiff_t dvalue;
-    dim(std::ptrdiff_t size) : dvalue(size) {}
+    dim_t(std::ptrdiff_t size) : dvalue(size) {}
 };
 
+template <std::ptrdiff_t N>
+constexpr std::enable_if_t<(N >= 0),dim_t<N>> dim() noexcept {
+    return dim_t<N>();
+}
+
+template <std::ptrdiff_t N = dynamic_range>
+constexpr std::enable_if_t<N == dynamic_range,dim_t<N>> dim(std::ptrdiff_t n) noexcept {
+    return dim_t<>(n);
+}
+
 template <typename ValueType, std::ptrdiff_t FirstDimension = dynamic_range,
           std::ptrdiff_t... RestDimensions>
 class multi_span;
@@ -1133,13 +1143,13 @@ namespace details
     }
     template <typename T, typename Arg, typename... Args>
     std::enable_if_t<
-        !std::is_same<Arg, dim<dynamic_range>>::value && !std::is_same<Arg, Sep>::value, T>
+        !std::is_same<Arg, dim_t<dynamic_range>>::value && !std::is_same<Arg, Sep>::value, T>
         static_as_multi_span_helper(Arg, Args... args)
     {
         return static_as_multi_span_helper<T>(args...);
     }
     template <typename T, typename... Args>
-    T static_as_multi_span_helper(dim<dynamic_range> val, Args... args)
+    T static_as_multi_span_helper(dim_t<dynamic_range> val, Args... args)
     {
         return static_as_multi_span_helper<T>(args..., val.dvalue);
     }
@@ -1682,7 +1692,7 @@ constexpr auto as_multi_span(multi_span<byte, Dimensions...> s) noexcept
 }
 
 template <typename T, std::ptrdiff_t... Dimensions>
-constexpr auto as_multi_span(T* const& ptr, dim<Dimensions>... args)
+constexpr auto as_multi_span(T* const& ptr, dim_t<Dimensions>... args)
     -> multi_span<std::remove_all_extents_t<T>, Dimensions...>
 {
     return {reinterpret_cast<std::remove_all_extents_t<T>*>(ptr),
diff --git a/tests/multi_span_tests.cpp b/tests/multi_span_tests.cpp
index 7432057..003d236 100644
--- a/tests/multi_span_tests.cpp
+++ b/tests/multi_span_tests.cpp
@@ -687,9 +687,9 @@ SUITE(multi_span_tests)
         fn(av.bounds());
         auto av2 = as_multi_span(av, dim<60>());
         auto av3 = as_multi_span(av2, dim<3>(), dim<4>(), dim<5>());
-        auto av4 = as_multi_span(av3, dim<4>(), dim<>(3), dim<5>());
+        auto av4 = as_multi_span(av3, dim<4>(), dim(3), dim<5>());
         auto av5 = as_multi_span(av4, dim<3>(), dim<4>(), dim<5>());
-        auto av6 = as_multi_span(av5, dim<12>(), dim<>(5));
+        auto av6 = as_multi_span(av5, dim<12>(), dim(5));
 
         fill(av6.begin(), av6.end(), 1);
 
@@ -954,7 +954,7 @@ SUITE(multi_span_tests)
 
             CHECK(s1 == s2);
 
-            multi_span<int, 20> s3 = as_multi_span(s1, dim<>(20));
+            multi_span<int, 20> s3 = as_multi_span(s1, dim(20));
             CHECK(s3 == s2 && s3 == s1);
         }
 
@@ -1122,7 +1122,7 @@ SUITE(multi_span_tests)
         CHECK(count == 34 * 60);
         overloaded_func(av, 34);
 
-        overloaded_func(as_multi_span(av, dim<>(4), dim<>(3), dim<>(5)), 34);
+        overloaded_func(as_multi_span(av, dim(4), dim(3), dim(5)), 34);
 
         // fixed_func(av, 34);
         delete[] data;
@@ -1137,7 +1137,7 @@ SUITE(multi_span_tests)
 
         // size check will be done
         auto image_view =
-            as_multi_span(as_multi_span(image_ptr, imgSize), dim<>(height), dim<>(width), dim<3>());
+            as_multi_span(as_multi_span(image_ptr, imgSize), dim(height), dim(width), dim<3>());
 
         iota(image_view.begin(), image_view.end(), 1);
 
@@ -1165,7 +1165,7 @@ SUITE(multi_span_tests)
         {
             int* arr = new int[150];
 
-            auto av = as_multi_span(arr, dim<10>(), dim<>(3), dim<5>());
+            auto av = as_multi_span(arr, dim<10>(), dim(3), dim<5>());
 
             fill(av.begin(), av.end(), 24);
             overloaded_func(av, 24);
@@ -1174,13 +1174,13 @@ SUITE(multi_span_tests)
 
             array<int, 15> stdarr{0};
             auto av2 = as_multi_span(stdarr);
-            overloaded_func(as_multi_span(av2, dim<>(1), dim<3>(), dim<5>()), 0);
+            overloaded_func(as_multi_span(av2, dim(1), dim<3>(), dim<5>()), 0);
 
             string str = "ttttttttttttttt"; // size = 15
             auto t = str.data();
             (void) t;
             auto av3 = as_multi_span(str);
-            overloaded_func(as_multi_span(av3, dim<>(1), dim<3>(), dim<5>()), 't');
+            overloaded_func(as_multi_span(av3, dim(1), dim<3>(), dim<5>()), 't');
         }
 
         {
@@ -1258,7 +1258,7 @@ SUITE(multi_span_tests)
 
         CHECK(av[i] == 4);
 
-        auto av2 = as_multi_span(av, dim<4>(), dim<>(2));
+        auto av2 = as_multi_span(av, dim<4>(), dim(2));
         ptrdiff_t a2[2] = {0, 1};
         index<2> i2 = a2;
 
@@ -1490,17 +1490,17 @@ SUITE(multi_span_tests)
 
         // first bound is dynamic
         {
-            multi_span<int, dynamic_range, 2> av2 = as_multi_span(av, dim<>(height), dim<>(width));
+            multi_span<int, dynamic_range, 2> av2 = as_multi_span(av, dim(height), dim(width));
             iterate_second_column(av2);
         }
         // second bound is dynamic
         {
-            multi_span<int, 4, dynamic_range> av2 = as_multi_span(av, dim<>(height), dim<>(width));
+            multi_span<int, 4, dynamic_range> av2 = as_multi_span(av, dim(height), dim(width));
             iterate_second_column(av2);
         }
         // both bounds are dynamic
         {
-            multi_span<int, dynamic_range, dynamic_range> av2 = as_multi_span(av, dim<>(height), dim<>(width));
+            multi_span<int, dynamic_range, dynamic_range> av2 = as_multi_span(av, dim(height), dim(width));
             iterate_second_column(av2);
         }
 
@@ -1521,7 +1521,7 @@ SUITE(multi_span_tests)
 
         CHECK_THROW(av1[10][3][4], fail_fast);
 
-        multi_span<const double, dynamic_range, 6, 4> av2 = as_multi_span(av1, dim<>(5), dim<6>(), dim<4>());
+        multi_span<const double, dynamic_range, 6, 4> av2 = as_multi_span(av1, dim(5), dim<6>(), dim<4>());
         (void) av2;
     }
 
@@ -1568,7 +1568,7 @@ SUITE(multi_span_tests)
 
         {
             multi_span<int, dynamic_range> av = arr;
-            multi_span<int, 2, 1> av2 = as_multi_span(av, dim<>(2), dim<>(2));
+            multi_span<int, 2, 1> av2 = as_multi_span(av, dim(2), dim(2));
             auto workaround_macro = [&]() { return av2[{1, 0}] == 2; };
             CHECK(workaround_macro());
         }
diff --git a/tests/strided_span_tests.cpp b/tests/strided_span_tests.cpp
index 19056b1..b81a5e7 100644
--- a/tests/strided_span_tests.cpp
+++ b/tests/strided_span_tests.cpp
@@ -463,7 +463,7 @@ SUITE(strided_span_tests)
 		// retype strided array with regular strides - from multi_span
 		{
 			strided_bounds<2> bounds{ { 2, bytes.size() / 4 }, { bytes.size() / 2, 1 } };
-			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim<>(bytes.size() / 2));
+			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim(bytes.size() / 2));
 			strided_span<const byte, 2> sav2{ bytes2, bounds };
 			strided_span<int, 2> sav3 = sav2.as_strided_span<int>();
 			CHECK(sav3[0][0] == 0);
@@ -475,7 +475,7 @@ SUITE(strided_span_tests)
 		// retype strided array with not enough elements - last dimension of the array is too small
 		{
 			strided_bounds<2> bounds{ { 4,2 },{ 4, 1 } };
-			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim<>(bytes.size() / 2));
+			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim(bytes.size() / 2));
 			strided_span<const byte, 2> sav2{ bytes2, bounds };
 			CHECK_THROW(sav2.as_strided_span<int>(), fail_fast);
 		}
@@ -483,7 +483,7 @@ SUITE(strided_span_tests)
 		// retype strided array with not enough elements - strides are too small
 		{
 			strided_bounds<2> bounds{ { 4,2 },{ 2, 1 } };
-			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim<>(bytes.size() / 2));
+			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim(bytes.size() / 2));
 			strided_span<const byte, 2> sav2{ bytes2, bounds };
 			CHECK_THROW(sav2.as_strided_span<int>(), fail_fast);
 		}
@@ -491,7 +491,7 @@ SUITE(strided_span_tests)
 		// retype strided array with not enough elements - last dimension does not divide by the new typesize
 		{
 			strided_bounds<2> bounds{ { 2,6 },{ 4, 1 } };
-			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim<>(bytes.size() / 2));
+			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim(bytes.size() / 2));
 			strided_span<const byte, 2> sav2{ bytes2, bounds };
 			CHECK_THROW(sav2.as_strided_span<int>(), fail_fast);
 		}
@@ -499,7 +499,7 @@ SUITE(strided_span_tests)
 		// retype strided array with not enough elements - strides does not divide by the new typesize
 		{
 			strided_bounds<2> bounds{ { 2, 1 },{ 6, 1 } };
-			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim<>(bytes.size() / 2));
+			multi_span<const byte, 2, dynamic_range> bytes2 = as_multi_span(bytes, dim<2>(), dim(bytes.size() / 2));
 			strided_span<const byte, 2> sav2{ bytes2, bounds };
 			CHECK_THROW(sav2.as_strided_span<int>(), fail_fast);
 		}
@@ -675,17 +675,17 @@ SUITE(strided_span_tests)
         }
 
         {
-            auto av = as_multi_span(as_multi_span(arr, 24), dim<>(3), dim<4>(), dim<2>());
+            auto av = as_multi_span(as_multi_span(arr, 24), dim(3), dim<4>(), dim<2>());
             iterate_second_slice(av);
         }
 
         {
-            auto av = as_multi_span(as_multi_span(arr, 24), dim<3>(), dim<>(4), dim<2>());
+            auto av = as_multi_span(as_multi_span(arr, 24), dim<3>(), dim(4), dim<2>());
             iterate_second_slice(av);
         }
 
         {
-            auto av = as_multi_span(as_multi_span(arr, 24), dim<3>(), dim<4>(), dim<>(2));
+            auto av = as_multi_span(as_multi_span(arr, 24), dim<3>(), dim<4>(), dim(2));
             iterate_second_slice(av);
         }
         delete[] arr;
@@ -704,7 +704,7 @@ SUITE(strided_span_tests)
         auto d1 = sizeof(int) * 12 / d2;
 
         // convert to 4x12 array of bytes
-        auto av = as_multi_span(as_bytes(as_multi_span(arr, 4)), dim<>(d1), dim<>(d2));
+        auto av = as_multi_span(as_bytes(as_multi_span(arr, 4)), dim(d1), dim(d2));
 
         CHECK(av.bounds().index_bounds()[0] == 4);
         CHECK(av.bounds().index_bounds()[1] == 12);