text: //------------------------------------------------------------------------------
  // GrB_Vector_assign_[SCALAR]: assign scalar to vector, via scalar expansion
  //------------------------------------------------------------------------------
  
  // SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2021, All Rights Reserved.
  // SPDX-License-Identifier: Apache-2.0
  
  //------------------------------------------------------------------------------
  
  // Assigns a single scalar to a vector, w<M>(Rows) = accum(w(Rows),x)
  // The scalar x is implicitly expanded into a vector u of size nRows-by-1,
  // with each entry in u equal to x.
  
  #include "GB_assign.h"
  #include "GB_ij.h"
  #include "GB_get_mask.h"
  
  #define GB_ASSIGN_SCALAR(prefix,type,T,ampersand)                              \
  GrB_Info GB_EVAL3 (prefix, _Vector_assign_, T) /* w<M>(Rows)=accum(w(Rows),x)*/\
  (                                                                              \
      GrB_Vector w,                   /* input/output vector for results      */ \
      const GrB_Vector M,             /* optional mask for w                  */ \
      const GrB_BinaryOp accum,       /* optional accum for Z=accum(w(Rows),x)*/ \
      type x,                         /* scalar to assign to w(Rows)          */ \
      const GrB_Index *Rows,          /* row indices                          */ \
      GrB_Index nRows,                /* number of row indices                */ \
      const GrB_Descriptor desc       /* descriptor for w and mask            */ \
  )                                                                              \
  {                                                                              \
      GB_WHERE (w, "GrB_Vector_assign_" GB_STR(T)                                \
          " (w, M, accum, x, Rows, nRows, desc)") ;                              \
      GB_BURBLE_START ("GrB_assign") ;                                           \
      GB_RETURN_IF_NULL_OR_FAULTY (w) ;                                          \
      GB_RETURN_IF_FAULTY (M) ;                                                  \
      ASSERT (GB_VECTOR_OK (w)) ;                                                \
      ASSERT (GB_IMPLIES (M != NULL, GB_VECTOR_OK (M))) ;                        \
      GrB_Info info = GB_assign_scalar ((GrB_Matrix) w, (GrB_Matrix) M, accum,   \
          ampersand x, GB_## T ## _code, Rows, nRows, GrB_ALL, 1, desc,          \
          Context) ;                                                             \
      GB_BURBLE_END ;                                                            \
      return (info) ;                                                            \
  }
  
  GB_ASSIGN_SCALAR (GrB, bool      , BOOL   , &)
  GB_ASSIGN_SCALAR (GrB, int8_t    , INT8   , &)
  GB_ASSIGN_SCALAR (GrB, uint8_t   , UINT8  , &)
  GB_ASSIGN_SCALAR (GrB, int16_t   , INT16  , &)
  GB_ASSIGN_SCALAR (GrB, uint16_t  , UINT16 , &)
  GB_ASSIGN_SCALAR (GrB, int32_t   , INT32  , &)
  GB_ASSIGN_SCALAR (GrB, uint32_t  , UINT32 , &)
  GB_ASSIGN_SCALAR (GrB, int64_t   , INT64  , &)
  GB_ASSIGN_SCALAR (GrB, uint64_t  , UINT64 , &)
  GB_ASSIGN_SCALAR (GrB, float     , FP32   , &)
  GB_ASSIGN_SCALAR (GrB, double    , FP64   , &)
  GB_ASSIGN_SCALAR (GxB, GxB_FC32_t, FC32   , &)
  GB_ASSIGN_SCALAR (GxB, GxB_FC64_t, FC64   , &)
  GB_ASSIGN_SCALAR (GrB, void *    , UDT    ,  )
  
  //------------------------------------------------------------------------------
  // GrB_Vector_assign_Scalar: assign a GrB_Scalar to a matrix
  //------------------------------------------------------------------------------
  
  // If the GrB_Scalar s is non-empty, then this is the same as the non-opapue
  // scalar subassignment above.
  
  // If the GrB_Scalar s is empty of type stype, then this is identical to:
  //  GrB_Vector_new (&S, stype, nRows) ;
  //  GrB_Vector_assign (w, M, accum, S, Rows, nRows, desc) ;
  //  GrB_Vector_free (&S) ;
  
  #define GB_FREE_ALL GB_phbix_free (S) ;
  
  GB_PUBLIC
  GrB_Info GrB_Vector_assign_Scalar   // w<Mask>(I) = accum (w(I),s)
  (
      GrB_Vector w,                   // input/output matrix for results
      const GrB_Vector M_in,          // optional mask for w, unused if NULL
      const GrB_BinaryOp accum,       // optional accum for Z=accum(w(I),x)
      GrB_Scalar scalar,              // scalar to assign to w(I)
      const GrB_Index *I,             // row indices
      GrB_Index ni,                   // number of row indices
      const GrB_Descriptor desc       // descriptor for w and Mask
  )
  {
  
      //--------------------------------------------------------------------------
      // check inputs
      //--------------------------------------------------------------------------
  
      GrB_Matrix S = NULL ;
      GB_WHERE (w, "GrB_Vector_assign_Scalar"
          " (w, M, accum, s, Rows, nRows, desc)") ;
      GB_BURBLE_START ("GrB_assign") ;
      GB_RETURN_IF_NULL_OR_FAULTY (w) ;
      GB_RETURN_IF_NULL_OR_FAULTY (scalar) ;
      GB_RETURN_IF_FAULTY (M_in) ;
      ASSERT (GB_VECTOR_OK (w)) ;
      ASSERT (M_in == NULL || GB_VECTOR_OK (M_in)) ;
  
      // get the descriptor
      GB_GET_DESCRIPTOR (info, desc, C_replace, Mask_comp, Mask_struct,
          xx1, xx2, xx3, xx7) ;
  
      // get the mask
      GrB_Matrix M = GB_get_mask ((GrB_Matrix) M_in, &Mask_comp, &Mask_struct) ;
  
      //--------------------------------------------------------------------------
      // w<M>(Rows) = accum (w(Rows), scalar)
      //--------------------------------------------------------------------------
  
      GrB_Index nvals ;
      GB_OK (GB_nvals (&nvals, (GrB_Matrix) scalar, Context)) ;
      if (nvals == 1)
      { 
  
          //----------------------------------------------------------------------
          // the opaque GrB_Scalar has a single entry
          //----------------------------------------------------------------------
  
          // This is identical to non-opaque scalar subassignment
  
          info = (GB_assign (
              (GrB_Matrix) w, C_replace,  // w vector and its descriptor
              M, Mask_comp, Mask_struct,  // mask vector and its descriptor
              false,                      // do not transpose the mask
              accum,                      // for accum (w(Rows),scalar)
              NULL, false,                // no explicit vector u
              I, ni,                      // row indices
              GrB_ALL, 1,                 // column indices
              true,                       // do scalar expansion
              scalar->x,                  // scalar to assign, expands to become u
              scalar->type->code,         // type code of scalar to expand
              GB_ASSIGN,
              Context)) ;
  
      }
      else
      { 
  
          //----------------------------------------------------------------------
          // the opaque GrB_Scalar has no entry
          //----------------------------------------------------------------------
  
          // determine the properites of the I index list
          int64_t nRows, RowColon [3] ;
          int RowsKind ;
          GB_ijlength (I, ni, GB_NROWS (w), &nRows, &RowsKind, RowColon);
  
          // create an empty matrix S of the right size, and use matrix assign
          struct GB_Matrix_opaque S_header ;
          S = GB_clear_static_header (&S_header) ;
          GB_OK (GB_new (&S, true, scalar->type, nRows, 1, GB_Ap_calloc,
              true, GxB_AUTO_SPARSITY, GB_HYPER_SWITCH_DEFAULT, 1, Context)) ;
          info = GB_assign (
              (GrB_Matrix) w, C_replace,      // w vector and its descriptor
              M, Mask_comp, Mask_struct,      // mask matrix and its descriptor
              false,                          // do not transpose the mask
              accum,                          // for accum (w(Rows),scalar)
              S, false,                       // S matrix and its descriptor
              I, ni,                          // row indices
              GrB_ALL, 1,                     // column indices
              false, NULL, GB_ignore_code,    // no scalar expansion
              GB_ASSIGN,
              Context) ;
          GB_FREE_ALL ;
      }
  
      GB_BURBLE_END ;
      return (info) ;
  }
  
  