Not quite as good as I’d hoped, but you can do some fun things with __typeof__.

autotes.m

// cc autotes.m -o autotes -framework Foundation -fobjc-arc && ./autotes
#import <Foundation/Foundation.h>

// use it like lambda(…args…)(…return value…)
#define lambda(...) \
	^(__VA_ARGS__) _lambda_body

#define _lambda_body(...) \
	{ return __VA_ARGS__; }


#define autotes(v, ...) \
	__typeof__(__VA_ARGS__) v = (__VA_ARGS__)


int main(int argc, const char *argv[]) {
	@autoreleasepool {
		// riffing off @CodaFi’s combinatorial riff off lambda()()
		
		autotes(I, lambda(id x)(x));
		typedef __typeof__(I) I_t;
		
		autotes(K, lambda(id x)(lambda(id y)(x)));
		
		autotes(S, lambda(I_t(^x)(I_t))(lambda(I_t(^y)(I_t))(lambda(id z)(x(z)(y(z))))));
	}
	return EXIT_SUCCESS;
}