QGIS » QGIS Application

If you have a PostgreSQL table (with geom type or not) :

CREATE TABLE public.t_bool(
id INTEGER CONSTRAINT t_bool_pkey PRIMARY KEY,
fld BOOLEAN
);

INSERT INTO public.t_bool (id, fld) VALUES (1, True), (2, False), (3, False), (4, True);

and try to paste it as a memory layer, QGIS display an error message :

Can't create the field fld (bool,bool)

Moreover, when you create an empty memory layer, you can't add a boolean field type.