utDataAssign

float[] buf = [ 1.1, 2.2, 3.3, 4.4, 5.5, 6.6 ];

struct vec3 { double[3] dd; alias dd this; }

utDataAssign( ElemInfo( 3, DataType.FLOAT ), cast(void*)(buf.ptr+1), vec3([8,9,10]) );

assert( eq( buf, [1.1,8,9,10,5.5,6.6] ) );