good-smart-pointer.cpp
author František Kučera <franta-hg@frantovo.cz>
Wed, 30 Oct 2024 22:08:49 +0100
changeset 2 64777e5b619f
parent 1 4502b1c7346d
permissions -rw-r--r--
class Finally with lambda
     1 /**
     2  * cpp-finally
     3  * Copyright © 2024 František Kučera (Frantovo.cz, GlobalCode.info)
     4  *
     5  * This program is free software: you can redistribute it and/or modify
     6  * it under the terms of the GNU General Public License as published by
     7  * the Free Software Foundation, version 3 of the License.
     8  *
     9  * This program is distributed in the hope that it will be useful,
    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  * GNU General Public License for more details.
    13  *
    14  * You should have received a copy of the GNU General Public License
    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
    16  */
    17 
    18 #include <iostream>
    19 #include <exception>
    20 #include <memory>
    21 
    22 /** not needed, just for logging */
    23 void* myMalloc(size_t size) {
    24 	void* ptr = ::malloc(size);
    25 	std::cout << "  allocated memory at: " << ptr << std::endl;
    26 	return ptr;
    27 }
    28 
    29 /** not needed, just for logging */
    30 void myFree(void* ptr) {
    31 	::free(ptr);
    32 	std::cout << "  freed memory at: " << ptr << std::endl;
    33 }
    34 
    35 void fxThrowing(bool fail, void* data) {
    36 	std::cout << "  doing something with data " << data << std::endl;
    37 	if (fail) throw std::logic_error("error from fxThrowing()");
    38 }
    39 
    40 void fxAllocating(bool fail) {
    41 	// std::shared_ptr<void> buf(malloc(486), free); // standard functions
    42 	std::shared_ptr<void> buf(myMalloc(486), myFree); // our ones with logging
    43 	fxThrowing(fail, buf.get());
    44 }
    45 
    46 int main(int argc, char** argv) {
    47 	bool fail = argc == 2 && std::string("fail") == argv[1];
    48 	const char* name = "good-smart-pointer";
    49 	std::cout << name << " (fail=" << fail << ")\n";
    50 	try {
    51 		fxAllocating(fail);
    52 	} catch (const std::exception& e) {
    53 		std::cout << "  caught exception: " << e.what() << std::endl;
    54 	}
    55 }