Add argmin and argmax (#470)

* Add argmin and argmax

README.md

@@ -301,6 +301,8 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `find` is now `findall` ([#25545]).
 
+* `indmin` and `indmax` are now `argmin` and `argmax`, respectively ([#25654]).
+
 ## New macros
 
 * `@__DIR__` has been added ([#18380])
@@ -484,3 +486,4 @@ includes this fix. Find the minimum version from there.
 [#25545]: https://github.com/JuliaLang/julia/issues/25545
 [#25571]: https://github.com/JuliaLang/julia/issues/25571
 [#25629]: https://github.com/JuliaLang/julia/issues/25629
+[#25654]: https://github.com/JuliaLang/julia/issues/25654

src/Compat.jl

@@ -1304,6 +1304,12 @@ if !isdefined(Base, :findall)
     export findall
 end
 
+@static if !isdefined(Base, :argmin)
+    const argmin = indmin
+    const argmax = indmax
+    export argmin, argmax
+end
+
 @static if !isdefined(Base, :parentmodule)
     parentmodule(m::Module) = Base.module_parent(m)
     parentmodule(f::Function) = Base.function_module(f)

test/runtests.jl

@@ -1168,6 +1168,10 @@ module TestLibdl
     @test isdefined(@__MODULE__, :Libdl)
 end
 
+# 0.7.0-DEV.3516
+@test argmax([10,12,9,11]) == 2
+@test argmin([10,12,9,11]) == 3
+
 # 0.7.0-DEV.3415
 @test findall(x -> x==1, [1, 2, 3, 2, 1]) == [1, 5]