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import org.checkerframework.checker.nullness.qual.*;
// This is the example from manual section:
// "Generics (parametric polymorphism or type polymorphism)"
// whose source code is ../../../docs/manual/advanced-features.tex
class GenericsExample {
class MyList1<@Nullable T> {
T t;
@Nullable T nble;
@NonNull T nn;
MyList1(T t, @Nullable T nble, @NonNull T nn) {
this.t = t;
this.nble = nble;
this.nn = nn;
}
void add(T arg) {}
T get(int i) {
return t;
}
void m() {
t = null;
t = nble;
nble = null;
// :: error: (assignment.type.incompatible)
nn = null;
t = this.get(0);
nble = this.get(0);
// :: error: (assignment.type.incompatible)
nn = this.get(0);
this.add(t);
this.add(nble);
this.add(nn);
}
}
class MyList1a<@Nullable T extends @Nullable Object> {
T t;
@Nullable T nble;
@NonNull T nn;
MyList1a(T t, @Nullable T nble, @NonNull T nn) {
this.t = t;
this.nble = nble;
this.nn = nn;
}
void add(T arg) {}
T get(int i) {
return t;
}
void m() {
t = null;
t = nble;
nble = null;
// :: error: (assignment.type.incompatible)
nn = null;
t = this.get(0);
nble = this.get(0);
// :: error: (assignment.type.incompatible)
nn = this.get(0);
this.add(t);
this.add(nble);
this.add(nn);
}
}
class MyList2<@NonNull T extends @NonNull Object> {
T t;
@Nullable T nble;
@NonNull T nn;
MyList2(T t, @Nullable T nble, @NonNull T nn) {
this.t = t;
this.nble = nble;
this.nn = nn;
}
void add(T arg) {}
T get(int i) {
return t;
}
void m() {
// :: error: (assignment.type.incompatible)
t = null;
// :: error: (assignment.type.incompatible)
t = nble;
nble = null;
// :: error: (assignment.type.incompatible)
nn = null;
t = this.get(0);
nble = this.get(0);
nn = this.get(0);
this.add(t);
// :: error: (argument.type.incompatible)
this.add(nble);
this.add(nn);
}
}
class MyList2a<T extends @NonNull Object> { // same as MyList2
T t;
@Nullable T nble;
@NonNull T nn;
MyList2a(T t, @Nullable T nble, @NonNull T nn) {
this.t = t;
this.nble = nble;
this.nn = nn;
}
void add(T arg) {}
T get(int i) {
return t;
}
void m() {
// :: error: (assignment.type.incompatible)
t = null;
// :: error: (assignment.type.incompatible)
t = nble;
nble = null;
// :: error: (assignment.type.incompatible)
nn = null;
t = this.get(0);
nble = this.get(0);
nn = this.get(0);
this.add(t);
// :: error: (argument.type.incompatible)
this.add(nble);
this.add(nn);
}
}
class MyList3<T extends @Nullable Object> {
T t;
@Nullable T nble;
@NonNull T nn;
MyList3(T t, @Nullable T nble, @NonNull T nn) {
this.t = t;
this.nble = nble;
this.nn = nn;
}
void add(T arg) {}
T get(int i) {
return t;
}
void m() {
// :: error: (assignment.type.incompatible)
t = null;
// :: error: (assignment.type.incompatible)
t = nble;
nble = null;
// :: error: (assignment.type.incompatible)
nn = null;
t = this.get(0);
nble = this.get(0);
// :: error: (assignment.type.incompatible)
nn = this.get(0);
this.add(t);
// :: error: (argument.type.incompatible)
this.add(nble);
this.add(nn);
}
}
}
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