Play around with NSMethodSignature and @encode

signature.m

#import <Foundation/Foundation.h>

// clang -g -Wall -framework Foundation -o signature signature.m


// A class with a vararg, and non-vararg method, to see if the method signatures
// are different.  (don't expect them to be, but ya never know...)
@interface VarBork : NSObject
- (id) gronkVar: (float) hoover, ...;
- (id) gronk: (float) hoover;
@end // VarBork

@implementation VarBork
- (id) gronkVar: (float) hoover, ... { return nil; }
- (id) gronk: (float) hoover { return nil; }
@end // VarBork


// Little utility to dump out a method signature.
static void printSignature (NSMethodSignature *signature) {
    printf ("%ld arguments\n", [signature numberOfArguments]);
    for (NSUInteger i = 0; i < [signature numberOfArguments]; i++) {
        printf ("%ld -> %s\n", i, [signature getArgumentTypeAtIndex: i]);
    }
    printf ("returning %s\n\n", [signature methodReturnType]);

} // printSignature


int main (void) {
    NSMethodSignature *signature =
        [NSString instanceMethodSignatureForSelector: @selector(rangeOfCharacterFromSet:options:range:)];
    printf ("rangeOfCharacterFromSet:options:range:\n");
    printSignature (signature);

    printf ("looking at encodings\n");
    printf ("int:        %s\n", @encode(int));
    printf ("CGRect:     %s\n", @encode(CGRect));
    printf ("NSString *: %s\n\n", @encode(NSString *));


    // Explore varargs
    signature =
        [NSMutableString instanceMethodSignatureForSelector: @selector(appendFormat:)];
    printf ("appendFormat:\n");
    printSignature (signature);

    signature =
        [VarBork instanceMethodSignatureForSelector: @selector(gronk:)];
    printf ("gronk:\n");
    printSignature (signature);

    signature =
        [VarBork instanceMethodSignatureForSelector: @selector(gronkVar:)];
    printf ("gronkVar:...\n");
    printSignature (signature);

    return 0;
} // main