A double-ended priority queue in STL style.
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This project is my implementation of a priority deque (double-ended priority queue) as a C++ class template.


  • Interface similar to STL.
    • Status: Complete.
    • priority_deque implements the std::priority_queue interface.
    • Additional functions, for double-ended access and random-access among others, are in STL style.
  • Interface in Boost style.
    • Status: Incomplete.
  • Performance competitive with STL's priority_queue.
    • Status: Close.
    • Benchmarks indicate ~20% slower performance in push, ~15% slower in pop. (GCC, -O3)
    • Bulk-loading is optionally threaded, with the following benchmarked performance ratios (deque time : queue time, smaller is better):
      • 1.228 : 1 (1 CPU core)
      • 0.874 : 1 (2 CPU cores)
      • 0.545 : 1 (4 CPU cores)
  • Provide the strongest exception-safety guarantee possible without compromising performance.
    • Status: Complete.
    • Most operations, including provide the strong (rollback) exception-safety guarantee if comparison throws.
    • Bulk-loading operations such as merge cannot provide this guarantee without compromising performance.
    • The random-access update method can only provide the strong guarantee by copying an element or using move semantics.
  • Provide thread safety comparable to that of STL structures.
    • Status: Complete.
    • Functions have no side-effects besides the obvious (deque or interval heap may be altered), and can safely be called in threads, though a single queue should not be accessed by multiple threads simultaneously. Multiple reads are okay; simultaneous read-write and write-write may cause race conditions.