# Get fieldnames and values of \`struct\` as NamedTuple

**URL:** <https://discourse.julialang.org/t/get-fieldnames-and-values-of-struct-as-namedtuple/8991>\
**Category:** General Usage\
**Created:** [February 11, 2018, 12:49pm UTC](https://discourse.julialang.org/t/get-fieldnames-and-values-of-struct-as-namedtuple/8991 "2018-02-11T12:49:26Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![foobar\_lv2](https://avatars.discourse-cdn.com/v4/letter/f/ee59a6/32.png) [@foobar\_lv2](https://discourse.julialang.org/u/foobar_lv2)\
**Post date:** [February 11, 2018, 11:55pm UTC](https://discourse.julialang.org/t/get-fieldnames-and-values-of-struct-as-namedtuple/8991/3 "2018-02-11T23:55:32Z")

</div>

I had quite some fun with this one. I think the recommended way is the following way via generated functions (you proposed the naive way):

```julia
to_named_tuple_naive(p) = (; (v=>getfield(p, v) for v in fieldnames(typeof(p)))...)

gentup(struct_T) = NamedTuple{( fieldnames(struct_T)...,), Tuple{(fieldtype(struct_T,i) for i=1:fieldcount(struct_T))...}}

@generated function to_named_tuple_generated(x)
           nt = Expr(:quote, gentup(x))
           tup = Expr(:tuple)
           for i=1:fieldcount(x)
               push!(tup.args, :(getfield(x, $i)) )
           end
           return :($nt($tup))
       end

```

So, let’s compare!

```julia
using BenchmarkTools
struct Person
       age::Float64
       name::String
       end

struct point
    x::Float64 
    y::Float64 
end
pers=Person(34, "Jane")
pt = point(3.4, 4.5)
@show to_named_tuple_naive(pers);
#to_named_tuple_naive(pers) = (age = 34.0, name = "Jane")
@show to_named_tuple_generated(pers);
#to_named_tuple_generated(pers) = (age = 34.0, name = "Jane")

@btime to_named_tuple_naive($pers);
#4.471 ��s (25 allocations: 1.27 KiB)
@btime to_named_tuple_naive($pt);
#2.772 ��s (21 allocations: 1.17 KiB)

@btime to_named_tuple_generated($pers);
#8.554 ns (1 allocation: 32 bytes)
@btime to_named_tuple_generated($pt);
#2.208 ns (0 allocations: 0 bytes)

```

PS.

```julia
versioninfo()
#Julia Version 0.7.0-DEV.3943
#Commit dcc39f4d8d* (2018-02-09 22:47 UTC)

```

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