There is one prototype of syr
            available, please see below. 
syr( const Scalar >, const VectorX& x, MatrixA& a );
            syr (short for symmetric
            rank-1 update) provides a C++ interface to BLAS routines SSYR and DSYR.
            syr performs the symmetric
            rank 1 operation
          
A := alpha*x*x' + A,
where alpha is a real scalar, x is an n element vector and A is an n by n symmetric matrix.
            The selection of the BLAS routine is done during compile-time, and is
            determined by the type of values contained in type VectorX.
            The type of values is obtained through the value_type
            meta-function typename value_type<VectorX>::type. Table X below illustrates to
            which specific routine this dispatching will take place.
          
Table 1.68. Dispatching of syr.
| Value type of VectorX | BLAS routine | CBLAS routine | CUBLAS routine | 
|---|---|---|---|
| 
                       | SSYR | cblas_ssyr | cublasSsyr | 
| 
                       | DSYR | cblas_dsyr | cublasDsyr | 
            The original routines SSYR and DSYR have seven arguments, whereas syr requires three arguments.
          
            Defined in header boost/numeric/bindings/blas/level2/syr.hpp.
          
Parameters
The definition of term 1
The definition of term 2
The definition of term 3.
Definitions may contain paragraphs.
#include <boost/numeric/bindings/blas/level2/syr.hpp> using namespace boost::numeric::bindings; blas::syr( x, y, z );
this will output
[5] 0 1 2 3 4 5