F2003 supported ALLOCATE( A, SOURCE=B) where the dynamic type of B determined the dynamic type of A plus where the values where copied from B to A.
Fortran 2008 now also offers MOLD= where only the type is used, but no data is copied. Fortran 2008 draft FDIS: ftp://ftp.nag.co.uk/sc22wg5/N1801-N1850/N1814.pdf R626 allocate-stmt is ALLOCATE ( [ type-spec :: ] allocation-list [, alloc-opt-list ] ) R627 alloc-opt is ERRMSG = errmsg-variable or MOLD = source-expr or SOURCE = source-expr or STAT = stat-variable "If MOLD= appears and source-expr is a variable, its value need not be defined." And in the introduction one finds the following: "A structure constructor can omit the value for an allocatable component. SOURCE= in an ALLOCATE statement can give an array variable the bounds as well as the value of an expression. MOLD= in an ALLOCATE statement can give a polymorphic variable the shape, type, and type parameters of an expression without copying the value." -- Summary: [F2008][OOP] ALLOCATE with MOLD= Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: burnus at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43388
