Proposal: implicitly typed array creation expression with size

[Tan90909090]

Background

We have several ways to create array.

Firstly, we can specify array size:

var withSize = new int[3] { 1, 2, 3 };

Compiler detects a mismatch between specified size and array-initializer's length and reports an error:

// compile error
var mismatch = new int[1] { 1, 2, 3 };

Secondly, we can omit element type. Compiler infers element type:

var inferred = new[] { 1, 2, 3 };

Problem

Currently, we can not combine both features:

// syntax error
var ng = new[3] { 1, 2, 3 };

Proposal

Let's allow implicitly typed array creation expression with size.
Syntax may change like this:

array_creation_expression
    : 'new' non_array_type '[' expression_list ']' rank_specifier* array_initializer?
    | 'new' array_type array_initializer
    | 'new' rank_specifier array_initializer
+   | 'new' '[' expression_list ']' array_initializer
    ;

[jnm2]

Problem

Currently, we can not combine both features

Is this a problem? I think this is a feature, not a bug.

[yaakov-h]

Let's allow implicitly typed array creation expression with size.

Why?

[brandon942]

Why not javascript like simplicity with type and size inference?

var a = [1d, 2, 3, 4, 5, 6]; // let first element determine type