WIPnext

1 files changed, 41 insertions, 7 deletions

diff --git a/util.h b/util.h
index 62e7c4e..bba74a2 100644
--- a/util.h
+++ b/util.h
@@ -18,15 +18,49 @@
 #ifndef STREAMER_UTIL_H_
 #define STREAMER_UTIL_H_
 
-#define MIN(a, b) ((a) < (b) ? (a) : (b))
-#define MAX(a, b) ((a) > (b) ? (a) : (b))
-
-#define LENGTH(x) (sizeof(x) / sizeof *(x))
-
 #define STR_IMPL(x) #x
 #define STR(x) STR_IMPL(x)
+#define FROM_HERE __FILE__ ":" STR(__LINE__) " "
+
+template <class T>
+struct Defer {
+  Defer(T&& op) : op_{op} {}
+  ~Defer() { op_(); }
+  const T& op_;
+};
+
+template <class T>
+Defer(T&&) -> Defer<T>;
+
+template <auto dflt, auto closer>
+struct PodCloser {
+  struct pointer {
+    decltype(dflt) value_;
+    pointer() : value_{dflt} {}
+    pointer(decltype(nullptr)) : value_{dflt} {}
+    pointer(decltype(dflt) value) : value_{value} {}
+    explicit operator bool() const { return value_ != dflt; }
+    friend bool operator==(pointer, pointer) = default;
+    operator decltype(dflt)() const { return value_; }
+  };
+  void operator()(const pointer ptr) {
+    if (ptr.value_ != dflt) closer(ptr.value_);
+  }
+};
+
+template <class T>
+struct ClassOf;
+
+template <class R, class C>
+struct ClassOf<R C::*> {
+  using T = C;
+};
 
-#define LOG(x, ...) \
-  fprintf(stderr, __FILE__ ":" STR(__LINE__) " " x "\n", ##__VA_ARGS__)
+template <auto fun, class T, class... Args>
+inline auto Trampoline(T* head, Args... tail) {
+  using C = ClassOf<decltype(fun)>::T;
+  auto self = static_cast<C*>(head);
+  return (self->*fun)(tail...);
+}
 
 #endif  // STREAMER_UTIL_H_