Warns on construction of specific temporary objects in the Zircon kernel. If the object should be flagged, If the object should be flagged, the fully qualified type name must be explicitly passed to the check.

For example, given the list of classes “Foo” and “NS::Bar”, all of the following will trigger the warning:

Foo F = Foo();

namespace NS {



With the same list, the following will not trigger the warning:

Foo F;                                         // Non-temporary construction okay
Foo F(param);                      // Non-temporary construction okay
Foo *F = new Foo();      // New construction okay

Bar();                                         // Not NS::Bar, so okay
NS::Bar B;                           // Non-temporary construction okay

Note that objects must be explicitly specified in order to be flagged, and so objects that inherit a specified object will not be flagged.

This check matches temporary objects without regard for inheritance and so a prohibited base class type does not similarly prohibit derived class types.

class Derived : Foo {} // Derived is not explicitly disallowed
Derived();             // and so temporary construction is okay



A semi-colon-separated list of fully-qualified names of C++ classes that should not be constructed as temporaries. Default is empty.