Add cuMatArray::to_string, use it to refactor cuMatArray::display and add it to the C interface.

src/cuMatArray.h

@@ -11,6 +11,8 @@
 #include <algorithm>
 #include <cassert>
 #include <type_traits>
+#include <string>
+#include <cstdio>
 
 //TODO: function to get nrows, ncols of a list matrix
 //TODO: function to get nnz of a list sparse matrix
@@ -45,6 +47,8 @@ struct cuMatArray
 	 * Displays the the list of factors according to op.
 	 */
 	void display(gm_Op op=OP_NOTRANSP);
+
+	std::string  to_string(gm_Op op=OP_NOTRANSP);
 	/**
 	 * Computes the chain matrix product in cu_array applying the op (transpose, etc.) to it and if out is not nullptr it receives the result.
 	 * The product is computed from the right factor to the left.

src/cuMatArray.hpp

@@ -35,7 +35,13 @@ int32_t cuMatArray<T>::ncols() const
 template<typename T>
 void cuMatArray<T>::display(gm_Op op)
 {
-	//	std::cout << "gm::display" << std::endl;
+	std::cout << to_string(op) << std::endl;
+}
+
+template<typename T>
+std::string cuMatArray<T>::to_string(gm_Op op)
+{
+	std::string out_str="";
 	std::vector<int> im(cu_array.size());
 	for(int i=0;i<cu_array.size();i++) im[i] = i;
 	if(op != OP_NOTRANSP)
@@ -43,15 +49,18 @@ void cuMatArray<T>::display(gm_Op op)
 	for(int i : im)
 	{
 //#ifdef DEBUG
-		std::cout << "- GPU FACTOR " << i << ((std::is_same<T,cuComplex>::value || std::is_same<T,cuDoubleComplex>::value)?" (complex)":" (real)") << (cu_array[i]->is_sparse?" SPARSE":" DENSE") << " size ";
-		std::cout << (op == OP_NOTRANSP?cu_array[i]->nrows:cu_array[i]->ncols);
-		std::cout << " x " << (op == OP_NOTRANSP?cu_array[i]->ncols:cu_array[i]->nrows);
-		std::cout << ", addr: " << cu_array[i];
-		std::cout << ", density " << ((double)cu_array[i]->get_nnz())/cu_array[i]->nrows/cu_array[i]->ncols
-			<< ", nnz " << cu_array[i]->get_nnz()
-			<< std::endl;
+		out_str += std::string("- GPU FACTOR ") + std::to_string(i) + ((std::is_same<T,cuComplex>::value || std::is_same<T,cuDoubleComplex>::value)?" (complex)":" (real)") + (cu_array[i]->is_sparse?" SPARSE":" DENSE") + " size ";
+		out_str += std::to_string(op == OP_NOTRANSP?cu_array[i]->nrows:cu_array[i]->ncols);
+		out_str += std::string(" x ") + std::to_string(op == OP_NOTRANSP?cu_array[i]->ncols:cu_array[i]->nrows);
+		out_str += std::string(", addr: "); 
+//		std::to_string(static_cast<void*>(cu_array[i]));
+		char addr[sizeof(void*)+1];
+		std::sprintf(addr, "%p", cu_array[i]);
+		out_str += std::string((const char*)addr);
+		out_str += std::string(", density ") + std::to_string(((double)cu_array[i]->get_nnz())/cu_array[i]->nrows/cu_array[i]->ncols) + ", nnz " + std::to_string(cu_array[i]->get_nnz());
 //#endif
 	}
+	return out_str;
 }
 
 template<typename T>

src/gm.cpp.in

@@ -594,6 +594,18 @@ extern "C"
 		return static_cast<cuMatArray<@GM_SCALAR@>*>(array)->display();
 	}
 
+	__DYNLIB_ATTR__ const char* gm_MatArray_to_string_@GM_SCALAR@(gm_MatArray_t array)
+	{
+		//TODO: ideally a pre-allocated str should be passed by the caller (no allocation inside this function)
+		//TODO: until that the caller is responsible to free the returned memory buffer
+		std::string out_str = static_cast<cuMatArray<@GM_SCALAR@>*>(array)->to_string();
+		size_t len = out_str.size();
+		char * str_copy = (char*) malloc(len+1);
+		strncpy(str_copy, out_str.c_str(), len+1);
+		str_copy[len] = '\0';
+		return str_copy;
+	}
+
 	__DYNLIB_ATTR__ size_t gm_MatArray_get_total_nnz_@GM_SCALAR@(gm_MatArray_t array)
 	{
 		return static_cast<cuMatArray<@GM_SCALAR@>*>(array)->get_total_nnz();

src/gm_interf_gen.h.in

@@ -241,6 +241,7 @@ typedef void (*gm_MatArray_addgpu_anymat_@GM_SCALAR@_ptr)(gm_MatArray_t, void* a
 typedef int32_t (*gm_MatArray_nrows_@GM_SCALAR@_ptr)(gm_MatArray_t);
 typedef int32_t (*gm_MatArray_ncols_@GM_SCALAR@_ptr)(gm_MatArray_t);
 typedef void (*gm_MatArray_display_@GM_SCALAR@_ptr)(gm_MatArray_t);
+typedef const char* (*gm_MatArray_to_string_@GM_SCALAR@_ptr)(gm_MatArray_t);
 typedef size_t (*gm_MatArray_get_total_nnz_@GM_SCALAR@_ptr)(gm_MatArray_t);
 typedef void (*gm_MatArray_transpose_@GM_SCALAR@_ptr)(gm_MatArray_t);
 typedef void (*gm_MatArray_scalar_mul_@GM_SCALAR@_ptr)(gm_MatArray_t, const @GM_SCALAR@* scalar);
@@ -280,6 +281,7 @@ struct gm_MatArrayFunc_@GM_SCALAR@
 	gm_MatArray_nrows_@GM_SCALAR@_ptr nrows;
 	gm_MatArray_get_total_nnz_@GM_SCALAR@_ptr get_total_nnz;
 	gm_MatArray_display_@GM_SCALAR@_ptr display;
+	gm_MatArray_to_string_@GM_SCALAR@_ptr to_string;
 	/** Array computation functions */
 	gm_MatArray_matmul_@GM_SCALAR@_ptr chain_matmul;
 	gm_MatArray_matmul_one_@GM_SCALAR@_ptr chain_matmul_one;

src/gm_interf_gen.hpp.in

@@ -125,6 +125,7 @@ void load_marr_funcs_@GM_SCALAR@(void* gm_handle, gm_MatArrayFunc_@GM_SCALAR@ *m
 	 marr_funcs->nrows = (gm_MatArray_nrows_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_nrows_@GM_SCALAR@");
 	 marr_funcs->ncols = (gm_MatArray_ncols_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_ncols_@GM_SCALAR@");
 	 marr_funcs->display = (gm_MatArray_display_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_display_@GM_SCALAR@");
+	 marr_funcs->to_string = (gm_MatArray_to_string_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_to_string_@GM_SCALAR@");
 	 marr_funcs->chain_matmul_one = (gm_MatArray_matmul_one_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_matmul_one_@GM_SCALAR@");
 	 marr_funcs->get_total_nnz = (gm_MatArray_get_total_nnz_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_get_total_nnz_@GM_SCALAR@");
 	 marr_funcs->transpose = (gm_MatArray_transpose_@GM_SCALAR@_ptr) gm_load_func_check_err(gm_handle, "gm_MatArray_transpose_@GM_SCALAR@");