testing for deprecation

[Cauterite via Digitalmars-d-learn]

How does one test whether a symbol is deprecated? I would have 
expected something like: __traits(isDeprecated, foo).

In the compiler we have Dsymbol.isDeprecated, is that not 
accessible in any way from code?

The only solution I can think of is compiling with -de and using 
__traits(compiles, {alias x = foo;})
which actually does seem to work. Pretty lousy though.