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Calls the given function with the given arguments.  The trace will use
$name as the name of the function.

See L</"Prototypes"> for description of the $proto argument.

=item mcall( $class, $method, $proto, @ARGS )

=item mcall( $object, $method, $proto, @ARGS )

Calls the given method with the given arguments.

See L</"Prototypes"> for description of the $proto argument.

=item trace( $symbol, $prototype )

Replaces the function given by $symbol with a wrapped function.

=back

=head2 Prototypes

B<Note: The prototype string syntax described here is experimental and
likely to change in revisions of this interface>.

The $proto argument to call() and mcall() can optionally provide a
prototype for the function call.  This give the tracer hints about how
to best format the argument lists and if there are I<in/out> or I<out>
arguments.  The general form for the prototype string is:

   <arguments> = <return_value>

The default prototype is "@ = @"; list of values as input and list of
values as output.

The value '%' can be used for both arguments and return value to say
that key/value pair style lists are used.

Alternatively, individual positional arguments can be listed each
represented by a letter:

=over

=item C<i>

input argument

=item C<o>

output argument

=item C<O>

both input and output argument

=back

If the return value prototype has C<!> appended, then it signals that
this function sets errno ($!) when it returns a false value.  The
trace will display the current value of errno in that case.

If the return value prototype looks like a variable name (with C<$>
prefix), and the function returns a blessed object, then the variable
name will be used as prefix and the returned object automatically
traced.

=head1 SEE ALSO

L<Data::Dump>

=cut