ConsoleApplication2.cpp

// ConsoleApplication2.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include "pch.h"
#include <cstdio>
#include <cstdlib>
#include <string>
#include <sstream>

void StringInvalidParameterHandler(
	const wchar_t* expression,
	const wchar_t* function,
	const wchar_t* file,
	unsigned int line,
	uintptr_t pReserved);

void Examples();

template <size_t size>
errno_t strncpy_security(char (&destination)[size],
						 char const* source,
						 size_t _Count)
{
	return strncpy_s(destination, source, _Count);
}

int main()
{
	_invalid_parameter_handler oldHandler, newHandler;

	newHandler = StringInvalidParameterHandler;
	oldHandler = _set_invalid_parameter_handler(newHandler);

	// Disable the message box for assertions.
	_CrtSetReportMode(_CRT_ASSERT, 0);

	Examples();
}

void Examples()
{
	char dest[10];
	errno_t err = strncpy_s(dest, _countof(dest), "How do you do?", _TRUNCATE);
	printf("    truncation %s occur\n", err == STRUNCATE ? "did" : "did not");

	err = strncpy_s(dest, _countof(dest), "Howdy.", _TRUNCATE);
	printf("    truncation %s occur\n", err == STRUNCATE ? "did" : "did not");

	strncpy_security(dest, "very very very long", 15);

	printf("    new contents of dest: '%s'\n", dest);
}

void StringInvalidParameterHandler(
	const wchar_t* expression,
	const wchar_t* function,
	const wchar_t* file,
	unsigned int line,
	uintptr_t pReserved)
{
	printf("[%s:%ld] in %s\n", __func__, __LINE__, __FILE__);
	wprintf(L"Invalid parameter handler invoked: %s\n", expression);
}