一个好的C++模板程序

来自：使用IDA分析高级数据结构

#include <stdio.h> #include <malloc.h> // our structures // ============== // information about our customers struct customer_t { // a typical structure long id; char name[32]; char sex; // 'm'ale - 'f'emale }; // we sell books struct book_t { char title[128]; // an ASCII string }; // and we sell computer softwares struct software_info_t { // a structure containing various bitfields unsigned int plateform : 2; // 2 bits reserved for the plateform - // plateforms can be combined (0x03)#define PC 0x1 // 0x01 #define MAC 0x2 // 0x02 unsigned int os : 3; // 3 bits reserved for the OS - // OS can be combined (0x1C) #define WINDOWS 0x1 // 0x04 #define DOS 0x2 // 0x08 #define OS_X 0x4 // 0x10 unsigned int category : 2; // 2 bits reserved for the category - // categories can't be combined (0x60) #define DISASSEMBLY 0x1 // 0x20 #define RECOVERY 0x2 // 0x40 #define CRYPTOGRAPHY 0x3 // 0x60 }; struct software_t { software_info_t info; char name[32]; }; struct softwares_t { int iNum;software_t softs[];};// generic products we're selling enum product_category_t { // an enumerated type BOOK, SOFTWARE, HARDWARE // we actually don't sell hardware }; union product_u { // an union to contain product information // depending on its category book_t book; software_t software; // struct hardware_t hardware; // we actually don't sell hardware }; struct product_t { // a structure containing another structure long id; product_category_t category; product_u p; }; // our data // ======== // our customers customer_t customers[] = { // an initialized array to memorize our customers { 1, "Peter", 'm' }, { 2, "John", 'm' }, { 3, "Mary", 'f' }, { 0 } }; // our products book_t ida_book = { "IDA QuickStart Guide" }; softwares_t softwares = // an initialized variable length structure { 3, { { { PC, WINDOWS|DOS, DISASSEMBLY }, "IDA Pro" }, { { PC|MAC, WINDOWS|OS_X, RECOVERY }, "PhotoRescue" }, { { PC, WINDOWS, CRYPTOGRAPHY }, "aCrypt" } } }; #define PRODUCTS_COUNT 4 // our functions // ============= // check software information int check_software(software_info_t software_info) { bool valid = true; if (software_info.plateform & PC) { if (! (software_info.plateform & MAC) && (software_info.os & OS_X)) valid = false; // OS-X isn't yet available on PC ;) } else if (software_info.plateform & MAC) { if (! (software_info.plateform & PC) && ((software_info.os & WINDOWS) || (software_info.os & DOS))) valid = false; // Windows & DOS aren't available on Mac... } else valid = false; return valid; } // check product category int check_product(product_category_t product_category) { bool valid = true; if (product_category == HARDWARE) { valid = false; printf("We don't sell hardware for the moment...\n"); } return valid; } // print customer information void print_customer(customer_t *customer) { printf("CUSTOMER %04X: %s (%c)\n", customer->id, customer->name, customer->sex); } // print book information void print_book(book_t *book) { printf("BOOK: %s\n", book->title); } // print software information void print_software(software_t *software) { printf("SOFTWARE: %s:", software->name); // plateform // we use 'if', as plateforms can be combined if (software->info.plateform & PC) printf(" PC"); if (software->info.plateform & MAC) printf(" MAC"); printf(";"); // OS // we use 'if', as os can be combined if (software->info.os & WINDOWS) printf(" WINDOWS"); if (software->info.os & DOS) printf(" DOS"); if (software->info.os & OS_X) printf(" OS-X"); printf(";"); // category // we use 'switch', as categories can't be combined switch(software->info.category) { case DISASSEMBLY: printf(" DISASSEMBLY"); break; case RECOVERY: printf(" RECOVERY"); break; case CRYPTOGRAPHY: printf(" CRYPTOGRAPHY"); break; } printf("\n"); } // print product information bool print_product(product_t *product) { if (! check_product(product->category)) return false; printf("PRODUCT %04X: ", product->id); switch(product->category) { case BOOK: print_book(&product->p.book); break; case SOFTWARE: print_software(&product->p.software); break; } return true; } // our main program // ================ void main() { // print customers listing printf("CUSTOMERS:\n"); customer_t *customer = customers; while (customer->id != 0) { print_customer(customer); customer++; } // allocate a small array to store our products in memory product_t *products = (product_t*) malloc(PRODUCTS_COUNT * sizeof(product_t)); // insert our products products[0].id = 1; products[0].category = BOOK; products[0].p.book = ida_book; products[1].id = 2; products[1].category = SOFTWARE; products[1].p.software = softwares.softs[0]; // we insert softwares from our // variable length structure products[2].id = 3; products[2].category = SOFTWARE; products[2].p.software = softwares.softs[1]; products[3].id = 4; products[3].category = SOFTWARE; products[3].p.software = softwares.softs[2]; // verify and print each product printf("\nPRODUCTS:\n"); for (int i = 0; i < PRODUCTS_COUNT; i++) { // check validity of the product category if (! check_product(products[i].category)) { printf("Invalid product !!!\n"); break; } // check validity of softwares if (products[i].category == SOFTWARE) { if (! check_software(products[i].p.software.info)) { printf("Invalid software !!!\n"); break; } } // and print the product print_product(&products[i]); } free(products); }