add NamedTuple(itr) constructor (JuliaLang#37454)

NEWS.md

@@ -77,6 +77,7 @@ New library features
 --------------------
 
 * The `redirect_*` functions can now be called on `IOContext` objects.
+* New constructor `NamedTuple(iterator)` that constructs a named tuple from a key-value pair iterator.
 
 Standard library changes
 ------------------------

base/docs/basedocs.jl

@@ -2393,6 +2393,17 @@ another named tuple.
 """
 NamedTuple{names}(nt::NamedTuple)
 
+"""
+ NamedTuple(itr)
+
+Construct a named tuple from an iterator of key-value pairs (where the keys must be
+`Symbol`s). Equivalent to `(; itr...)`.
+
+!!! compat "Julia 1.6"
+ This method requires at least Julia 1.6.
+"""
+NamedTuple(itr)
+
 """
  typeassert(x, type)
 

base/namedtuple.jl

@@ -104,6 +104,8 @@ end
 NamedTuple{names, T}(itr) where {names, T <: Tuple} = NamedTuple{names, T}(T(itr))
 NamedTuple{names}(itr) where {names} = NamedTuple{names}(Tuple(itr))
 
+NamedTuple(itr) = (; itr...)
+
 end # if Base
 
 length(t::NamedTuple) = nfields(t)

test/namedtuple.jl

@@ -156,6 +156,8 @@ let d = [:a=>1, :b=>2, :c=>3] # use an array to preserve order
  y = (w=30, z=40)
  @test (;t..., y...) == (x=1, y=20, w=30, z=40)
  @test (;t..., y=0, y...) == (x=1, y=0, w=30, z=40)
+
+ @test NamedTuple(d) === (a=1, b=2, c=3)
 end
 
 # inference tests