overloading - F# force an overload of System.String.Format -

i format string using system.string.format has 5 overloads:

string string.format(string format , object arg0 ) string string.format(string format , object arg0 , object arg1 ) string string.format(string format , object arg0 , object arg1 , object arg2 ) string string.format(string format , params object[] args ) string string.format(iformatprovider provider , string format , params object[] args ) 

i use fourth overload (the 1 takes array of objects) this:

let frm = "{0} - {1}" let args = [| 1; 2 |] system.string.format(frm, args) 

the problem args argument interpreted object , hence first overload called. correctly following error:

system.formatexception: index (zero based) must greater or equal 0 , less size of argument list. 

is there way force "correct" overload?

a more elegant variant of @john's answer add type annotation compiler automatic upcast on elements of array:

let frm = "{0} - {1}" let args : obj [] = [| 1; 2 |] system.string.format(frm, args)