Bug 16485 – Add trait for determining whether a member variable is static or not

We should probably have a trait in std.traits either for checking whether a member variable is static or for checking that it's not static. It's something that seems to have come up several times recently in D.Learn and stackoverflow. I don't know that this is the best implementation, since it was just quickly thrown together, but this would be one possible implementation: template isStaticMember(T, string memberName) if(__traits(hasMember, T, memberName)) { mixin("alias member = " ~ T.stringof ~ "." ~ memberName ~ ";"); enum isStaticMember = !__traits(compiles, member.offsetof); } class C { int foo; static int bar; } void main() { static assert(!isStaticMember!(C, "foo")); static assert(isStaticMember!(C, "bar")); } But the fact that it's the offsetof property that is the key is definitely non-obvious and not something that it's reasonable to expect that your average programmer is going to think of, so putting something like this in std.traits would definitely be beneficial.

Commits pushed to master at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/d79da1d3cac16043b3599a234875c20c9a9e7b0c Issue 16485 - Add trait for testing if a member is static. https://github.com/dlang/phobos/commit/eb92dc9a88cc8e3a787a6347bc7c58df62af2637 Merge pull request #5112 from sprinkle131313/is-static-member Issue 16485 - Add trait for testing if a member is static. merged-on-behalf-of: Jack Stouffer <[email protected]>

Commits pushed to stable at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/d79da1d3cac16043b3599a234875c20c9a9e7b0c Issue 16485 - Add trait for testing if a member is static. https://github.com/dlang/phobos/commit/eb92dc9a88cc8e3a787a6347bc7c58df62af2637 Merge pull request #5112 from sprinkle131313/is-static-member

Commits pushed to newCTFE at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/d79da1d3cac16043b3599a234875c20c9a9e7b0c Issue 16485 - Add trait for testing if a member is static. https://github.com/dlang/phobos/commit/eb92dc9a88cc8e3a787a6347bc7c58df62af2637 Merge pull request #5112 from sprinkle131313/is-static-member

Commits pushed to dmd-cxx at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/d79da1d3cac16043b3599a234875c20c9a9e7b0c Issue 16485 - Add trait for testing if a member is static. https://github.com/dlang/phobos/commit/eb92dc9a88cc8e3a787a6347bc7c58df62af2637 Merge pull request #5112 from sprinkle131313/is-static-member