review fixes

include/eve/concept/generator.hpp

@@ -21,12 +21,34 @@ namespace eve
   //! @concept generator
   //! The concept `generator<Constant>` is satisfied if `Constant` is built as a eve::constant_callable.
   //!
+  //! @tparam G Type of the generator to check.
+  //!
   //! @groupheader{Examples}
-  //!   - `eve::one`
+  //!   - `eve::one_t`
   //====================================================================================================================
   template<typename Constant>
   concept generator = requires { typename Constant::constant_callable_tag; };
-  //================================================================================================
+  //====================================================================================================================
+  //! @}
+  //====================================================================================================================
+
+  //====================================================================================================================
+  //! @ingroup simd_concepts
+  //! @{
+  //! @concept generator_from
+  //! The concept `generator_for` is satisfied if `G` satisfies eve::generator and can be called with a
+  //! `eve::as<T>` argument.
+  //!
+  //! @tparam G Type of the generator to check.
+  //! @tparam T Type of the argument to pass to the generator.
+  //!
+  //! @groupheader{Examples}
+  //!   - `eve::one_t` satisfies `generator_for<int>`
+  //!   - `eve::nbmantissabits_t` satisfies `generator_for<float>` but not `generator_for<int>`
+  //====================================================================================================================
+  template<typename G, typename T>
+  concept generator_for = generator<G> && requires(G g, as<T> t) { g(t); };
+  //====================================================================================================================
   //! @}
-  //================================================================================================
+  //====================================================================================================================
 }

include/eve/concept/substitute.hpp

@@ -20,8 +20,8 @@ namespace eve
   //! @brief Specify that a type can be used as a substitute for another type after calling
   //!        `eve::as_value` on a value of the first type.
   //================================================================================================
-  template<typename T, typename Target>
-  concept substitute_for = ((arithmetic_value<T> || relaxed_logical_value<T>) && requires { Target{std::declval<T>()}; }) || generator<T>;
+  template<typename S, typename Target>
+  concept substitute_for = generator_for<S, Target> || ((arithmetic_value<S> || relaxed_logical_value<S>) && requires(S s) { Target{s}; });
   //================================================================================================
   //! @}
   //================================================================================================

test/unit/api/tuple/algorithm/scan.cpp

@@ -20,7 +20,7 @@ TTS_CASE("Check return type of scan on tuples")
 {
   using w_t = eve::wide<kumi::tuple<char, int, double>>;
   auto plus = [](auto a, auto b) {
-    return w_t{ kumi::map(eve::add, a, b) };
+    return kumi::map(eve::add, a, b);
   };
 
   TTS_EXPR_IS((eve::scan(std::declval<w_t>(), plus, eve::zero)), w_t);
@@ -41,7 +41,7 @@ TTS_CASE_TPL( "Check behavior of scan", eve::test::scalar::all_types)
   w_t expected = kumi::map(eve::scan, x);
 
   auto plus = [](auto a, auto b) {
-    return w_t{ kumi::map(eve::add, a, b) };
+    return kumi::map(eve::add, a, b);
   };
 
   w_t actual_1 = eve::scan(x, plus, eve::zero);
@@ -70,7 +70,7 @@ TTS_CASE_TPL( "Check behavior of scan, same type", eve::test::scalar::all_types)
   w_t expected = kumi::map(eve::scan, x);
 
   auto plus = [](auto a, auto b) {
-    return w_t{ kumi::map(eve::add, a, b) };
+    return kumi::map(eve::add, a, b);
   };
 
   w_t actual_1 = eve::scan(x, plus, eve::zero);