Some programming languages (notably C++) permit a single function name
to be defined several times, for application in different contexts.
This is called overloading. When a function name is overloaded,
break function is not enough to tell GDB where you want
a breakpoint. If you realize this is a problem, you can use
something like break function(types) to specify which
particular version of the function you want. Otherwise, GDB offers
you a menu of numbered choices for different possible breakpoints, and
waits for your selection with the prompt >. The first two
options are always [0] cancel and [1] all. Typing 1
sets a breakpoint at each definition of function, and typing
0 aborts the break command without setting any new
breakpoints.
For example, the following session excerpt shows an attempt to set a
breakpoint at the overloaded symbol String::after.
We choose three particular definitions of that function name:
(gdb) b String::after
[0] cancel
[1] all
[2] file:String.cc; line number:867
[3] file:String.cc; line number:860
[4] file:String.cc; line number:875
[5] file:String.cc; line number:853
[6] file:String.cc; line number:846
[7] file:String.cc; line number:735
> 2 4 6
Breakpoint 1 at 0xb26c: file String.cc, line 867.
Breakpoint 2 at 0xb344: file String.cc, line 875.
Breakpoint 3 at 0xafcc: file String.cc, line 846.
Multiple breakpoints were set.
Use the "delete" command to delete unwanted
breakpoints.
(gdb)