HHVM 4.112 is released! This release marks the end of support for 4.106; HHVM 4.107–4.111 remain supported, as do the 4.80 and 4.102 LTS releases.


  • A new built-in method ReflectionTypeConstant::getTypeStructure() was added (it had already been available in HHVM, but previously not recognized by the typechecker).
  • Type constants on this (e.g. this::T) can now be used as reified generic type parameters. Note that the type this itself is still not allowed as a reified generic type parameter.

Breaking Changes

  • The typechecker now raises an error if the built-ins echo and print are used with arguments that are not int or string.
  • Fixed a bug where the typechecker would not correctly enforce generic type constraints on opaque type aliases (e.g. newtype X<T as arraykey> = T;). This may reveal some previously undetected errors.