libiir++: add further std::vector<> interfaces

In addition to C-style pointer-to-array and size arguments, allow for
C++-style std::vector<> interfaces. This also integrates nicely with
swig and allows the Python bindings to use native lists/tuples.

src/libiir++/000_TopSource.cc

@@ -16,6 +16,7 @@
 #include "iir++.h"
 
 // Below are all the includes used throughout the library.
+#include <alloca.h>
 #include <stdlib.h>
 
 namespace IIR {

src/libiir++/100_Coeff.cc

@@ -14,6 +14,24 @@ Coeff::Coeff(int nc, const double* c, int nd, const double* d)
 
 
 
+Coeff::Coeff(const std::vector<double>& c, const std::vector<double>& d)
+{
+    int nc, nd;
+    double* ac, * ad;
+
+    nc = c.size();
+    ac = static_cast<double*>(alloca(nc * sizeof(double)));
+    for(int i = 0; i < nc; ++i) ac[i] = c[i];
+
+    nd = d.size();
+    ad = static_cast<double*>(alloca(nd * sizeof(double)));
+    for(int i = 0; i < nd; ++i) ad[i] = d[i];
+
+    cc_ = iir_coeff_new(nc, ac, nd, ad);
+}
+
+
+
 Coeff::Coeff(const struct iir_coeff_t* cc)
 {
     cc_ = iir_coeff_copy(cc);

src/libiir++/100_Coeff.h

@@ -39,6 +39,14 @@ public:
     */
     Coeff(int nc, const double* c, int nd, const double* d);
 
+    /*! \brief Constructor with raw coefficients.
+
+    \param c Array of \a c coefficients, size ≥ 1.
+    \param d Array of \a d coefficients, size ≥ 1.
+
+    */
+    Coeff(const std::vector<double>& c, const std::vector<double>& d);
+
     /*! \brief Constructor from C library object.
 
     \param cc Pointer to existing coefficient object.