Test: add xNRM2 prototypes to C++ header

Author: christoph-conrads

TESTING/cpp/lapack.hpp

@@ -44,6 +44,9 @@
 
 extern "C"
 {
+	float snrm2_(lapack_int* n, const float* p, lapack_int* incx);
+	double dnrm2_(lapack_int* n, const double* p, lapack_int* incx);
+
 	void sgemm_(
 		char* transa, char* transb,
 		lapack_int* m, lapack_int* n, lapack_int* k,
@@ -1082,6 +1085,15 @@ inline integer_t xLASRTR(
 
 
 
+float xNRM2(integer_t n, const float* x, integer_t incx) {
+	return snrm2_(&n, x, &incx);
+}
+
+double xNRM2(integer_t n, const double* x, integer_t incx) {
+	return dnrm2_(&n, x, &incx);
+}
+
+
 inline integer_t xPSTRF(
 	char uplo, integer_t n, float* A, integer_t lda,
 	integer_t* p_piv, integer_t* p_rank, float tol,