[Type] Support structured binding for tuple-like types (#5208)

* [Type] Support structured binding for tuple-like types

* fix redefinition

* fix test

Sofa/framework/Type/src/sofa/type/Quat.h

@@ -116,7 +116,7 @@ class Quat
 
     static Quat identity()
     {
-        return Quat(0,0,0,1);
+        return Quat(0, 0, 0, 1);
     }
 
     void set(Real x, Real y, Real z, Real w)
@@ -147,7 +147,7 @@ class Quat
 
     void clear()
     {
-        set(0.0,0.0,0.0,1);
+        set(0, 0, 0, 1);
     }
 
     /// Convert the reference frame orientation into an orientation quaternion
@@ -311,6 +311,30 @@ class Quat
         return _q[index];
     }
 
+    template< std::size_t I >
+    [[nodiscard]] constexpr Real& get() & noexcept requires (I < 4)
+    {
+        return _q[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const Real& get() const& noexcept requires (I < 4)
+    {
+        return _q[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr Real&& get() && noexcept requires (I < 4)
+    {
+        return std::move(_q[I]);
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const Real&& get() const&& noexcept requires (I < 4)
+    {
+        return std::move(_q[I]);
+    }
+
     auto inverse() const -> Quat;
 
     auto quatToRotationVector() const -> Vec3;
@@ -462,3 +486,17 @@ extern template class SOFA_TYPE_API Quat<float>;
 #endif
 
 } // namespace sofa::type
+
+namespace std
+{
+
+template<class Real>
+struct tuple_size<::sofa::type::Quat<Real> > : integral_constant<size_t, 4> {};
+
+template<std::size_t I, class Real>
+struct tuple_element<I, ::sofa::type::Quat<Real> >
+{
+    using type = typename::sofa::type::Quat<Real>::value_type;
+};
+
+}

Sofa/framework/Type/src/sofa/type/RGBAColor.h

@@ -33,6 +33,8 @@
 #include <cassert>
 
 #include <sofa/type/fixed_array_algorithms.h>
+#include <sofa/type/StrongType.h>
+
 
 namespace sofa::type
 {
@@ -45,8 +47,9 @@ namespace sofa::type
 class SOFA_TYPE_API RGBAColor
 {
 public:
+    using value_type = float;
     static constexpr sofa::Size NumberOfComponents = 4;
-    using ComponentArray = std::array<float, NumberOfComponents>;
+    using ComponentArray = std::array<value_type, NumberOfComponents>;
 
     constexpr RGBAColor()
         : m_components{ 1.f, 1.f, 1.f, 1.f } {}
@@ -132,6 +135,30 @@ class SOFA_TYPE_API RGBAColor
         return m_components[i];
     }
 
+    template< std::size_t I >
+    [[nodiscard]] constexpr float& get() & noexcept requires (I < 4)
+    {
+        return m_components[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const float& get() const& noexcept requires (I < 4)
+    {
+        return m_components[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr float&& get() && noexcept requires (I < 4)
+    {
+        return std::move(m_components[I]);
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const float&& get() const&& noexcept requires (I < 4)
+    {
+        return std::move(m_components[I]);
+    }
+
     void set(float r, float g, float b, float a) ;
 
     bool operator==(const RGBAColor& b) const
@@ -209,7 +236,6 @@ class SOFA_TYPE_API RGBAColor
 
     static constexpr sofa::Size static_size = NumberOfComponents;
     static constexpr sofa::Size size() { return static_size; }
-    using value_type = float;
     using size_type = sofa::Size;
 
 private:
@@ -285,3 +311,18 @@ constexpr const RGBAColor& RGBAColor::gold()     { return g_gold  ; }
 
 
 } // namespace sofa::type
+
+
+namespace std
+{
+
+template<>
+struct tuple_size<::sofa::type::RGBAColor > : integral_constant<size_t, ::sofa::type::RGBAColor::NumberOfComponents> {};
+
+template<std::size_t I>
+struct tuple_element<I, ::sofa::type::RGBAColor >
+{
+    using type = ::sofa::type::RGBAColor::value_type;
+};
+
+}

Sofa/framework/Type/src/sofa/type/Vec.h

@@ -613,6 +613,30 @@ class Vec
         return elems[i];
     }
 
+    template< std::size_t I >
+    [[nodiscard]] constexpr reference get() & noexcept requires( I < N )
+    {
+        return elems[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const_reference get() const& noexcept requires( I < N )
+    {
+        return elems[I];
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr ValueType&& get() && noexcept requires( I < N )
+    {
+        return std::move(elems[I]);
+    }
+
+    template< std::size_t I >
+    [[nodiscard]] constexpr const ValueType&& get() const&& noexcept requires( I < N )
+    {
+        return std::move(elems[I]);
+    }
+
     // direct access to data
     constexpr const ValueType* data() const noexcept
     {
@@ -782,4 +806,13 @@ struct less< sofa::type::Vec<N,T> >
     }
 };
 
+template<sofa::Size N, class T>
+struct tuple_size<::sofa::type::Vec<N,T> > : integral_constant<size_t, N> {};
+
+template<std::size_t I, sofa::Size N, class T >
+struct tuple_element<I, ::sofa::type::Vec<N,T> >
+{
+    using type = T;
+};
+
 } // namespace std

Sofa/framework/Type/test/Quater_test.cpp

@@ -707,4 +707,12 @@ TEST(QuaterTest, QuaterdFromUnitVectors)
     EXPECT_NEAR(0.5894552112230939, quat1[3], errorThreshold);
 }
 
-
+TEST(QuaterTest, StructuredBindings)
+{
+    Quat<double> quat1;
+    const auto& [a,b,c,d] = quat1;
+    EXPECT_NEAR(0., a, errorThreshold);
+    EXPECT_NEAR(0., b, errorThreshold);
+    EXPECT_NEAR(0., c, errorThreshold);
+    EXPECT_NEAR(1., d, errorThreshold);
+}

Sofa/framework/Type/test/RGBAColor_test.cpp

@@ -44,6 +44,7 @@ class Color_Test : public BaseTest,
     void checkStreamingOperator(const std::vector<std::string>&) ;
     void checkDoubleStreamingOperator(const std::vector<std::string>&) ;
     void testEnlight();
+    void testStructuredBindings();
 };
 
 void Color_Test::testEnlight()
@@ -54,6 +55,15 @@ void Color_Test::testEnlight()
     EXPECT_EQ( RGBAColor::lighten(RGBAColor::red(), 0.5), RGBAColor(1.0,0.5,0.5,1.0) ) ;
 }
 
+void Color_Test::testStructuredBindings()
+{
+    const auto& [r, g, b, a] = RGBAColor::red();
+    EXPECT_EQ(r, 1.);
+    EXPECT_EQ(g, 0.);
+    EXPECT_EQ(b, 0.);
+    EXPECT_EQ(a, 1.);
+}
+
 void Color_Test::checkCreateFromString()
 {
     EXPECT_EQ( RGBAColor::fromString("white"), RGBAColor(1.0,1.0,1.0,1.0) ) ;
@@ -277,6 +287,11 @@ TEST_F(Color_Test, checkEnlight)
     this->testEnlight() ;
 }
 
+TEST_F(Color_Test, testStructuredBindings)
+{
+    this->testStructuredBindings();
+}
+
 std::vector<std::vector<std::string>> testvalues =
 {
     {"    0 0 0 0","0 0 0 0", "S"},

Sofa/framework/Type/test/VecTypes_test.cpp

@@ -23,4 +23,11 @@
 #include <sofa/defaulttype/VecTypes.h>
 #include <gtest/gtest.h>
 
-
+TEST(VecTest, StructuredBindings)
+{
+    constexpr sofa::type::Vec3 vec { 1.0, 2.0, 3.0 };
+    const auto& [a, b, c] = vec;
+    EXPECT_EQ(a, 1.);
+    EXPECT_EQ(b, 2.);
+    EXPECT_EQ(c, 3.);
+}