In the past, creating a collection of dates was a chore, because you had to individually insert them into a container (e.g. declaring a vector on one line and then pushing dates into it on subsequent lines). With features like std::initializer_list from C++11 onwards, it’s now much easier to do this concisely.
Here’s some simple, concise code to create dates without all the hassle:
struct Date
{
std::string Event;
int Year;
int Month;
int Day;
};
void print( const Date& date )
{
std::cout << date.Event << ": "<< date.Year << "/" << date.Month << "/" << date.Day << "\n";
}
void print( const std::vector<Date>& dates )
{
for ( auto date : dates )
{
print( date );
}
}
void test()
{
std::cout << "Print date:\n";
print( { "Today", 2015, 5, 5 } );
std::cout << "Print dates:\n";
print( {
{ "Christmas", 2015, 12, 25 },
{ "Spring Bank Holiday", 2016, 6, 30 }
} );
}
This style is particularly useful when writing tests – you can write a whole test, including setting up the data, on a single line (or at least, in a single function call).
Another compelling use case comes when creating test cases for graph algorithms. Suppose you have the following data structures for an undirected, weighted graph:
struct Edge
{
const size_t end1;
const size_t end2;
const size_t cost;
};
struct Graph
{
size_t source;
size_t nodes;
std::vector<Edge> edges;
};
Then creating a test graph to pass into an algorithm is as simple as:
shortest_path( { 0, 4, { {0,1,24}, {0,3,20}, {2,0,3}, {3,2,12} } })
This book tells the journey taken by the author in his attempts to find and interview all the remaining astronauts who have walked on the moon. Twelve men in history have known what it is like, and at the time of his writing, only nine were alive. The book describes the impact such an event had on the lives of the men.
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