fix build

Author: igagis

src/r4/vector.hpp

@@ -28,6 +28,7 @@ SOFTWARE.
 
 #include <array>
 
+#include <utki/config.hpp>
 #include <utki/debug.hpp>
 #include <utki/math.hpp>
 
@@ -674,7 +675,10 @@ class vector :
 	 * @param num - scalar to multiply by.
 	 * @return Reference to this vector object.
 	 */
-	constexpr vector& operator*=(component_type num) noexcept
+#if CFG_CPP >= 20
+	constexpr
+#endif
+	vector& operator*=(component_type num) noexcept
 	{
 		return this->comp_operation([&num](auto& a) {
 			return a * num;
@@ -687,7 +691,10 @@ class vector :
 	 * @param num - scalar to multiply by.
 	 * @return Vector resulting from multiplication of this vector by scalar.
 	 */
-	constexpr vector operator*(component_type num) const noexcept
+#if CFG_CPP >= 20
+	constexpr
+#endif
+	vector operator*(component_type num) const noexcept
 	{
 		return (vector(*this) *= num);
 	}
@@ -698,7 +705,10 @@ class vector :
 	 * @param num - scalar to divide by.
 	 * @return Vector resulting from division of this vector by scalar.
 	 */
-	constexpr vector operator/(component_type num) const noexcept
+#if CFG_CPP >= 20
+	constexpr
+#endif
+	vector operator/(component_type num) const noexcept
 	{
 		return vector(*this) /= num;
 	}
@@ -720,7 +730,10 @@ class vector :
 	 * @param num - scalar to divide by.
 	 * @return Reference to this vector object.
 	 */
-	constexpr vector& operator/=(component_type num) noexcept
+#if CFG_CPP >= 20
+	constexpr
+#endif
+	vector& operator/=(component_type num) noexcept
 	{
 		// TODO: uncomment when there is a solution to have the assertion in constexpr context
 		// utki::assert(num != 0, [&](auto& o) {

tests/unit/src/vector4.cpp

@@ -1,6 +1,7 @@
 #include <tst/set.hpp>
 #include <tst/check.hpp>
 
+#include <utki/config.hpp>
 #include <utki/string.hpp>
 
 #include "../../../src/r4/vector.hpp"
@@ -536,17 +537,21 @@ const tst::set set("vector4", [](tst::suite& suite){
     });
 
     suite.add("constexprness", [](){
+#if CFG_CPP >= 20
         // operator/(number)
         {
             constexpr auto v = r4::vector4<unsigned>(10, 20, 30, 40) / 2;
             tst::check_eq(v, r4::vector4<unsigned>(10, 20, 30, 40) / 2, SL);
         }
+#endif
 
+#if CFG_CPP >= 20
         // operator*(number)
         {
             constexpr auto v = r4::vector4<unsigned>(10, 20, 30, 40) * 2;
             tst::check_eq(v, r4::vector4<unsigned>(10, 20, 30, 40) * 2, SL);
         }
+#endif
 
         // TODO: add other operators and functions
     });