• Alexander Tretyak (6/6) Jun 25 2023 I'm just curious when was the `auto` keyword introduced in D?
• Adam D Ruppe (15/19) Jun 25 2023 What's New for D 0.137
• Alexander Tretyak (1/1) Jun 25 2023 Thanks for the reply!
• Patrick Schluter (14/21) Jun 26 2023 auto is a C keyword defining the storage class of a variable.

Alexander Tretyak <alextretyak2 gmail.com> writes:

I'm just curious when was the `auto` keyword introduced in D?

The reason I am asking is because D language appeared in 2001, 
but C++ 
[proposal](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1478.pdf)
with `auto` keyword new semantics dated April 28, 2003.

I always thought that `auto` in D was taken from C++. But what if 
it is opposite, i.e. C++11's `auto` was inspired by D's `auto`?

Adam D Ruppe <destructionator gmail.com> writes:

On Monday, 26 June 2023 at 00:00:48 UTC, Alexander Tretyak wrote:
 I'm just curious when was the `auto` keyword introduced in D?

  What's New for D 0.137
Oct 24, 2005
New/Changed Features

     Added implicit type inference.

from: https://digitalmars.com/d/1.0/changelog1.html


Though the auto keyword was around earlier (it actually comes 
from old C), and technically doesn't mean exactly what you think 
it means - the `auto` keyword isn't what's magic, you can use 
many others in its place (most the time) like `const` and 
`immutable` among more - but the feature referred to is the type 
inference.

 I always thought that `auto` in D was taken from C++. But what 
 if it is opposite, i.e. C++11's `auto` was inspired by D's 
 `auto`?

It probably went both ways. The C++ proposal you linked is 
definitely earlier than D adopting the thing, and perhaps D's use 
of it helped prompt the C++ committee to adopt it too.

Alexander Tretyak <alextretyak2 gmail.com> writes:

Thanks for the reply!

Patrick Schluter <Patrick.Schluter bbox.fr> writes:

On Monday, 26 June 2023 at 00:00:48 UTC, Alexander Tretyak wrote:
 I'm just curious when was the `auto` keyword introduced in D?

 The reason I am asking is because D language appeared in 2001, 
 but C++ 
 [proposal](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1478.pdf)
with `auto` keyword new semantics dated April 28, 2003.

 I always thought that `auto` in D was taken from C++. But what 
 if it is opposite, i.e. C++11's `auto` was inspired by D's 
 `auto`?

auto is a C keyword defining the storage class of a variable. 
It's placed at the same place as register/const and static.

In D it has the same role (i.e. it's a storage class). The type 
inference has nothing to do with auto. It is just necessary for 
the grammar to represent a type of a declaration.

     a=1;

if the type is omitted, the parser cannot distinguish between a 
declaration with initialiser or an assignment. You have to put 
either a type or a storage class to disambguate

    const a=1;
    immutabe b=2L;
    auto c=5.4;
    static d=w"Hello";