C++ OGR GDAL Set spatial reference of new layer

Question

When creating a new layer using OGR / GDAL in C++, how do i set the spatial reference?

OGRLayer  *poLayer2;
poLayer2 = poDS2->CreateLayer( "layerName", NULL, wkbPoint, NULL );
if( poLayer2 == NULL ) {
    printf( "Layer creation failed PODS2.\n" );
    exit( 1 );
}

Answer 1

Using the class & method reference for OGR Spatial Reference in combination with OGR tutorial, one should set a spatial reference and supply that (instead of NULL) as argument upon layer creation:

OGRLayer  *poLayer2;
OGRSpatialReference  *spatialReference;
//spatialReference.SetWellKnownGeogCS( "WGS84" );
spatialReference.SetWellKnownGeogCS( "EPSG:4326" ); 
poLayer2 = poDS2->CreateLayer( "layerName", spatialReference, wkbPoint, NULL );
if( poLayer2 == NULL ) {
    printf( "Layer creation failed PODS2.\n" );
    exit( 1 );
}

When cloning a layer, one can copy the spatial reference directly from original layer:

OGRLayer  *poLayer;
OGRLayer  *poLayer2;
... get poLayer from shapefile (not scope of this answer)
poLayer2 = poDS2->CreateLayer( poLayer->GetName(), poLayer->GetSpatialRef(), wkbPoint, NULL );