How to find all functions with methods for a given class

How to find all functions with methods for a given class

I’m basically looking for the opposite of methods(some_function) , which returns all class-methods that exist for that function. Is there some easy way to search for all functions which have an explicit method for a given object class?
For example, methods(my_func) returns a pile of myfunc.classname values. Is there a functions(my_class) which would return all functions with a func.my_class method?

I think you want to supply an argument to class and nothing to generic.function in methods. Compare

[1]    *             as.matrix.default                
[4] as.matrix.dist*                   as.matrix.noquote                 as.matrix.POSIXlt                
[7] as.matrix.raster*                 as.matrix.SpatialGridDataFrame*   as.matrix.SpatialPixelsDataFrame*

With this, which returns methods for the generic class

 [1] anyDuplicated.matrix* as.raster.matrix*     boxplot.matrix        corresp.matrix*      
 [7] determinant.matrix    duplicated.matrix     edit.matrix*          head.matrix           isSymmetric.matrix    lda.matrix*          
[13] qda.matrix*           relist.matrix*        subset.matrix         summary.matrix        tail.matrix           unique.matrix        

   Non-visible functions are asterisked

And this also seems to work for S4 classes as well, e.g.

 [1] $<*           [.data.table*             [<* **
 [6]**** *     
[11] dimnames<*****        
[16]**       names<** *