Skip to content

Add the DimensionCount trait. #2032

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ghost wants to merge 1 commit into from
Closed

Add the DimensionCount trait. #2032

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 24 additions & 0 deletions std/traits.d
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -114,6 +114,7 @@
* $(LREF PointerTarget)
* $(LREF KeyType)
* $(LREF ValueType)
* $(LREF DimensionCount)
* $(LREF Unsigned)
* $(LREF Largest)
* $(LREF Signed)
Expand Down Expand Up @@ -5920,6 +5921,29 @@ unittest
ValueType!Hash num = 1; // num is declared as int
}

/**
* Returns the dimension count of a static or dynamic array.
* Dimensions are counted up to the first non-array element type.
*/
enum DimensionCount(T : E[], E) = DimCountImpl!E + 1;

///
unittest
{
static assert(DimensionCount!(int[]) == 1);
static assert(DimensionCount!(int[][]) == 2);
static assert(DimensionCount!(int[1][ ]) == 2);
static assert(DimensionCount!(int[ ][1]) == 2);
static assert(DimensionCount!(int[1][1]) == 2);
static assert(DimensionCount!(int[][]*[]) == 1);

// can only be called on arrays
static assert(!__traits(compiles, DimensionCount!int));
}

private enum DimCountImpl(T : E[], E) = DimCountImpl!E + 1;
private enum DimCountImpl(T) = 0;

/**
* Returns the corresponding unsigned type for T. T must be a numeric
* integral type, otherwise a compile-time error occurs.
Expand Down