Re^3: &&= vivify keys?

[ikegami]

Actually, you're closer to the truth than Eliya is. The assignment is indeed conditional.

Aside from the syntax error from missing parens, the problems both yours and Eliya share are:

• 1 is actually evaluated before anything else,
• $x{a} is only evaluated once, and
• $x{a} is (only) evaluated in lvalue context.

See Re^2: &&= vivify keys?.