Get back to explicit default constructors and get rid of 'no_init'

The 10% performances lost is fixed doing so, which is quite unexpected

Fixes issue #4

src/algebra/TinyMatrix.hpp

@@ -36,7 +36,7 @@ public:
   PASTIS_INLINE
   constexpr TinyMatrix operator-() const
   {
-    TinyMatrix opposed{no_init};
+    TinyMatrix opposed;
     for (size_t i=0; i<N*N; ++i) {
       opposed.m_values[i] = -m_values[i];
     }
@@ -63,7 +63,7 @@ public:
   constexpr TinyMatrix operator*(const TinyMatrix& B) const
   {
     const TinyMatrix& A = *this;
-    TinyMatrix AB{no_init};
+    TinyMatrix AB;
     for (size_t i=0; i<N; ++i) {
       for (size_t j=0; j<N; ++j) {
         T sum = A(i,0)*B(0,j);
@@ -80,7 +80,7 @@ public:
   constexpr TinyVector<N,T> operator*(const TinyVector<N,T>& x) const
   {
     const TinyMatrix& A = *this;
-    TinyVector<N,T> Ax{no_init};
+    TinyVector<N,T> Ax;
     for (size_t i=0; i<N; ++i) {
       T sum = A(i,0)*x[0];
       for (size_t j=1; j<N; ++j) {
@@ -129,7 +129,7 @@ public:
   PASTIS_INLINE
   constexpr TinyMatrix operator+(const TinyMatrix& A) const
   {
-    TinyMatrix sum{no_init};
+    TinyMatrix sum;
     for (size_t i=0; i<N*N; ++i) {
       sum.m_values[i] = m_values[i]+A.m_values[i];
     }
@@ -148,7 +148,7 @@ public:
   PASTIS_INLINE
   constexpr TinyMatrix operator-(const TinyMatrix& A) const
   {
-    TinyMatrix difference{no_init};
+    TinyMatrix difference;
     for (size_t i=0; i<N*N; ++i) {
       difference.m_values[i] = m_values[i]-A.m_values[i];
     }
@@ -232,8 +232,10 @@ public:
     this->_unpackVariadicInput(t, std::forward<Args>(args)...);
   }
 
+  // One does not use the '=default' constructor to avoid (unexpected)
+  // performances issues
   PASTIS_INLINE
-  constexpr TinyMatrix() noexcept = default;
+  constexpr TinyMatrix() noexcept {}
 
   PASTIS_INLINE
   constexpr TinyMatrix(const ZeroType&) noexcept
@@ -255,11 +257,6 @@ public:
     }
   }
 
-  // Default constructor helper. Used to define uninitialized TinyMatrix
-  // avoiding compiler's false uninitialized warning.
-  PASTIS_INLINE
-  constexpr TinyMatrix(const NoInitType&) noexcept {}
-
   PASTIS_INLINE
   constexpr TinyMatrix(const TinyMatrix&) noexcept = default;
 
@@ -275,7 +272,7 @@ PASTIS_INLINE
 constexpr TinyMatrix<N,T> tensorProduct(const TinyVector<N,T>& x,
                                         const TinyVector<N,T>& y)
 {
-  TinyMatrix<N,T> A{no_init};
+  TinyMatrix<N,T> A;
   for (size_t i=0; i<N; ++i) {
     for (size_t j=0; j<N; ++j) {
       A(i,j) = x[i]*y[j];
@@ -292,7 +289,7 @@ constexpr T det(const TinyMatrix<N,T>& A)
   static_assert(std::is_floating_point<T>::value, "determinent for arbitrary dimension N is defined for floating point types only");
   TinyMatrix<N,T> M = A;
 
-  TinyVector<N, size_t> index{no_init};
+  TinyVector<N, size_t> index;
   for (size_t i=0; i<N; ++i) index[i]=i;
 
   T determinent = 1;
@@ -363,7 +360,7 @@ constexpr TinyMatrix<N-1,T> getMinor(const TinyMatrix<N,T>& A,
 {
   static_assert(N>=2, "minor calculation requires at least 2x2 matrices");
   Assert((I<N) and (J<N));
-  TinyMatrix<N-1,T> M{no_init};
+  TinyMatrix<N-1,T> M;
   for (size_t i=0; i<I; ++i) {
     for (size_t j=0; j<J; ++j) {
       M(i,j)=A(i,j);

src/algebra/TinyVector.hpp

@@ -31,7 +31,7 @@ class TinyVector
   PASTIS_INLINE
   constexpr TinyVector operator-() const
   {
-    TinyVector opposed{no_init};
+    TinyVector opposed;
     for (size_t i=0; i<N; ++i) {
       opposed.m_values[i] =-m_values[i];
     }
@@ -106,7 +106,7 @@ class TinyVector
   PASTIS_INLINE
   constexpr TinyVector operator+(const TinyVector& v) const
   {
-    TinyVector sum{no_init};
+    TinyVector sum;
     for (size_t i=0; i<N; ++i) {
       sum.m_values[i] = m_values[i]+v.m_values[i];
     }
@@ -125,7 +125,7 @@ class TinyVector
   PASTIS_INLINE
   constexpr TinyVector operator-(const TinyVector& v) const
   {
-    TinyVector difference{no_init};
+    TinyVector difference;
     for (size_t i=0; i<N; ++i) {
       difference.m_values[i] = m_values[i]-v.m_values[i];
     }
@@ -197,13 +197,10 @@ class TinyVector
     this->_unpackVariadicInput(t, std::forward<Args>(args)...);
   }
 
-  // Default constructor helper. Used to define uninitialized TinyVector
-  // avoiding compiler's false uninitialized warning.
+  // One does not use the '=default' constructor to avoid (unexpected)
+  // performances issues
   PASTIS_INLINE
-  constexpr TinyVector(const NoInitType&) noexcept {}
-
-  PASTIS_INLINE
-  constexpr TinyVector() noexcept = default;
+  constexpr TinyVector() noexcept {}
 
   PASTIS_INLINE
   constexpr TinyVector(const ZeroType&) noexcept

src/utils/Types.hpp

 #ifndef TYPES_HPP
 #define TYPES_HPP
 
-enum class NoInitType { no_init };
-constexpr NoInitType no_init=NoInitType::no_init;
-
 enum class ZeroType { zero };
 constexpr ZeroType zero=ZeroType::zero;