//------------------------------------------------------------------------------
// GxB_Monoid_terminal: return the terminal of a monoid (if any)
//------------------------------------------------------------------------------

// SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2019, All Rights Reserved.
// http://suitesparse.com   See GraphBLAS/Doc/License.txt for license.

//------------------------------------------------------------------------------

// not parallel: this function does O(1) work and is already thread-safe.

#include "GB.h"

GrB_Info GxB_Monoid_terminal        // return the monoid terminal
(
    bool *has_terminal,             // true if the monoid has a terminal value
    void *terminal,                 // returns the terminal of the monoid,
                                    // unmodified if has_terminal is false
    const GrB_Monoid monoid         // monoid to query
)
{ 

    //--------------------------------------------------------------------------
    // check inputs
    //--------------------------------------------------------------------------

    GB_WHERE ("GxB_Monoid_terminal (&has_terminal, &terminal, monoid)") ;
    GB_RETURN_IF_NULL (has_terminal) ;
    GB_RETURN_IF_NULL (terminal) ;
    GB_RETURN_IF_NULL_OR_FAULTY (monoid) ;
    ASSERT_OK (GB_check (monoid, "monoid for terminal", GB0)) ;

    //--------------------------------------------------------------------------
    // return the terminal
    //--------------------------------------------------------------------------

    (*has_terminal) = (monoid->terminal != NULL) ;
    if (*has_terminal)
    { 
        memcpy (terminal, monoid->terminal, monoid->op->ztype->size) ;
    }
    return (GrB_SUCCESS) ;
}

