Section 11.12 A String Class 297 f ri en d b oo l o pe to r!=(c on st S tr in g& x c on st S tr in g& y fr ie nd bo ol op er at or co ns t St ri ng x, co ns t St ri ng y) { r et ur n s tr cm p(x re p->s y re p->s != } re tu rn st rc mp x.r ep s, y.r ep s) 0; }; S tr in g o pe to r+(c on st S tr in g&, c on st S tr in g&); St ri ng op er at or co ns t St ri ng co ns t St ri ng S tr in g o pe to r+(c on st S tr in g&, c on st c r*); St ri ng op er at or co ns t St ri ng co ns t ch ar To save space, I have left the I/O and concatenation operations as exercises The main program simply exercises the S tr in g operators a bit: St ri ng S tr in g f St ri ng a S tr in g b St ri ng f(S tr in g a, St ri ng b) { a 2] = ´x a[2 x´; c r c = b 3]; ch ar b[3 c ou t