Add something (#562)

README.md

@@ -302,6 +302,9 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `isbits(t::Type)` is now `isbitstype(t)` ([#26850]).
 
+* `something` to get the first argument different from `nothing`, unwrapping those
+  of the `Some` type ([#27258]).
+
 ## Renaming
 
 * `Display` is now `AbstractDisplay` ([#24831]).
@@ -637,3 +640,4 @@ includes this fix. Find the minimum version from there.
 [#26670]: https://github.com/JuliaLang/julia/issues/26670
 [#26850]: https://github.com/JuliaLang/julia/issues/26850
 [#27077]: https://github.com/JuliaLang/julia/issues/27077
+[#27258]: https://github.com/JuliaLang/julia/issues/27258

src/Compat.jl

@@ -1877,6 +1877,14 @@ end
     export @cfunction
 end
 
+if VERSION < v"0.7.0-DEV.5278"
+    something() = throw(ArgumentError("No value arguments present"))
+    something(x::Nothing, y...) = something(y...)
+    something(x::Some, y...) = x.value
+    something(x::Any, y...) = x
+    export something
+end
+
 include("deprecated.jl")
 
 end # module Compat

test/runtests.jl

@@ -1743,4 +1743,10 @@ let ptr = @cfunction(+, Int, (Int, Int))
     @test ccall(ptr, Int, (Int, Int), 2, 3) == 5
 end
 
+# 0.7.0-DEV.5278
+@test something(nothing, 1) === 1
+@test something(Some(2)) === 2
+@test something(Some(2), 1) === 2
+@test something(nothing, Some(1)) === 1
+
 nothing