Add Optional::value_or_compute for lazy computation of default value

2019-01-03 22:49:40 +11:00 · 2019-01-03 22:49:40 +11:00 · 56ee329d79
commit 56ee329d79
parent 8a6a76fcd3
1 changed files with 3 additions and 0 deletions
--- a/src/optional.hh
+++ b/src/optional.hh
@ -84,6 +84,9 @@ public:
    template<typename U>
    T value_or(U&& fallback) const { return m_valid ? m_value : T{std::forward<U>(fallback)}; }

+    template<typename U>
+    T value_or_compute(U&& compute_func) const { return m_valid ? m_value : compute_func(); }
+
    void reset() { destruct_ifn(); m_valid = false; }

 private: