On 1/31/2019 1:46 PM, Andrei Alexandrescu wrote:
The proposal could actually disallow rvalues that have lvalue syntax, such as "symbol", "symbol[expr]", "symbol.symbol", "symbol.symbol[expr]", etc. Ugh. Gets hairy quickly.
That's why it's problematic to have a rule that rvalues can be implicitly converted, but not lvalues. There's not a hard line between lvalues and rvalues. For example,
foreach(i; 0..2) { int[] a = [1, 2]; assert(a[0] == 1]); a[0] = 3; // will this cause the assert to fail? }