sampler a;
sampler b;
sampler c = a;
void declare() { sampler d; }
void initialize() { sampler e = a; }
void assign() { a = b; }

/*%%*
opaque type 'sampler' cannot use initializer expressions
variables of type 'sampler' must be global
variables of type 'sampler' must be global
opaque type 'sampler' cannot use initializer expressions
assignments to opaque type 'sampler' are not permitted
*%%*/