Add {TinyVector,TinyMatrix}::data_type typename

This allows to access to the type of embedded data

src/algebra/TinyMatrix.hpp

@@ -12,6 +12,9 @@
 template <size_t N, typename T=double>
 class TinyMatrix
 {
+ public:
+  using data_type = T;
+
  private:
   T m_values[N*N];
   static_assert((N>0),"TinyMatrix size must be strictly positive");

src/algebra/TinyVector.hpp

@@ -13,6 +13,9 @@
 template <size_t N, typename T=double>
 class TinyVector
 {
+ public:
+  using data_type = T;
+
  private:
   T m_values[N];
   static_assert((N>0),"TinyVector size must be strictly positive");