# Inconsistent use of type parameters?
**URL:** https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544
**Category:** New to Julia
**Created:** [May 5, 2017, 5:45pm UTC](https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544 "2017-05-05T17:45:53Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@ndbecker](https://discourse.julialang.org/u/ndbecker)
#### Post date: [May 5, 2017, 5:45pm UTC](https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544/1 "2017-05-05T17:45:53Z")
struct A{T}
nothing
end
Can we use the name A without a parameter?
julia\> A
A
Yes, how about with a type parameter?
julia\> A{Int64}
A{Int64}
no problem. But:
function b{T}(x::T)
return x
end
b (generic function with 1 method)
Name ‘b’ without parameter?
julia\> b
b (generic function with 1 method)
yes, but
julia\> b{Int64}
ERROR: TypeError: Type{…} expression: expected UnionAll, got #b
Stacktrace:
[1] macro expansion at ./REPL.jl:97 [inlined]
[2] (::Base.REPL.##1#2{Base.REPL.REPLBackend})() at ./event.jl:73
Naming the function with a type parameter gives a (strange!) error
Seems inconsistent to this naive user, and the message seems mysterious.
---
### Author:  [@rdeits](https://discourse.julialang.org/u/rdeits)
#### Post date: [May 5, 2017, 5:48pm UTC](https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544/2 "2017-05-05T17:48:40Z")
I agree that this can be confusing. Fortunately, Julia v0.6 introduces a new syntax for `b`:
```julia
function b(x::T) where T
return x
end
```
which no longer (incorrectly) implies that you could write `b{Int}`.
---
### Author:  [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)
#### Post date: [May 5, 2017, 5:55pm UTC](https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544/3 "2017-05-05T17:55:21Z")
To expand on this a little, in Julia there are two types of constructors
- **Inner:** these accept type parameters (i.e. the arguments in the `{}`) and are declared inside the `type` declaration. i.e. they are called like `XType{T}(args...)`
- **Outer:** these do not take any type parameters and are declared outside of the `type` declaration. i.e. they are called like `XType(args...)`.
This seems quite confusing at first, but is actually quite useful as it is helpful to be able to declare either type of constructor. However, like @rdeits pointed out, there is now an additional syntax available for sorting this out.
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [May 5, 2017, 6:01pm UTC](https://discourse.julialang.org/t/inconsistent-use-of-type-parameters/3544/4 "2017-05-05T18:01:09Z")
The only “inconsistency” is that we don’t allow explicitly specifing the type parameters for a method. And that’s also related to that type cannot be overload but functions can.