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Comment by logicchains | Hacker News Reader

It says Zig eliminates "implicit conversions unless they are guaranteed to be safe (for example, assigning a u8 value to a u16 variable cannot fail or lose data)", but then suggests that @as should be used when "casting an int to a larger-size int of the same sign". Why should @as be used if it's safe to implicitly convert?

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What I took from the article is that it's useful when combined with type inference. So in Zig you could do:

  var x : u8 = 5;
  var y = @as(u32, x);

  var x : u8 = 5;
  var y : u32 = x;

The cast is needed in the first case to force the inference y: u32, otherwise it would be y: u8

Hmm, this indeed doesn't make much sense. Assigning to a wider type with or without different signedness doesn't require a cast as long as all bits fit into the new type:

https://www.godbolt.org/z/x8a65sPcr

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