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diff --git a/src/base/func_util.hh b/src/base/func_util.hh
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+/**
+ * Copyright (c) 2020, Timothy Stack
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * * Neither the name of Timothy Stack nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef lnav_func_util_hh
+#define lnav_func_util_hh
+
+#include <functional>
+#include <utility>
+
+template<typename F, typename FrontArg>
+decltype(auto)
+bind_mem(F&& f, FrontArg&& frontArg)
+{
+    return [f = std::forward<F>(f),
+            frontArg = std::forward<FrontArg>(frontArg)](auto&&... backArgs) {
+        return (frontArg->*f)(std::forward<decltype(backArgs)>(backArgs)...);
+    };
+}
+
+struct noop_func {
+    struct anything {
+        template<class T>
+        operator T()
+        {
+            return {};
+        }
+        // optional reference support.  Somewhat evil.
+        template<class T>
+        operator T&() const
+        {
+            static T t{};
+            return t;
+        }
+    };
+    template<class... Args>
+    anything operator()(Args&&...) const
+    {
+        return {};
+    }
+};
+
+namespace lnav {
+namespace func {
+
+class scoped_cb {
+public:
+    class guard {
+    public:
+        explicit guard(scoped_cb* owner) : g_owner(owner) {}
+
+        guard(const guard&) = delete;
+        guard& operator=(const guard&) = delete;
+
+        guard(guard&& gu) noexcept : g_owner(std::exchange(gu.g_owner, nullptr))
+        {
+        }
+
+        guard& operator=(guard&& gu) noexcept
+        {
+            this->g_owner = std::exchange(gu.g_owner, nullptr);
+            return *this;
+        }
+
+        ~guard()
+        {
+            if (this->g_owner != nullptr) {
+                this->g_owner->s_callback = {};
+            }
+        }
+
+    private:
+        scoped_cb* g_owner;
+    };
+
+    guard install(std::function<void()> cb)
+    {
+        this->s_callback = std::move(cb);
+
+        return guard{this};
+    }
+
+    void operator()()
+    {
+        if (s_callback) {
+            s_callback();
+        }
+    }
+
+private:
+    std::function<void()> s_callback;
+};
+
+template<typename Fn,
+         typename... Args,
+         std::enable_if_t<std::is_member_pointer<std::decay_t<Fn>>{}, int> = 0>
+constexpr decltype(auto)
+invoke(Fn&& f, Args&&... args) noexcept(
+    noexcept(std::mem_fn(f)(std::forward<Args>(args)...)))
+{
+    return std::mem_fn(f)(std::forward<Args>(args)...);
+}
+
+template<typename Fn,
+         typename... Args,
+         std::enable_if_t<!std::is_member_pointer<std::decay_t<Fn>>{}, int> = 0>
+constexpr decltype(auto)
+invoke(Fn&& f, Args&&... args) noexcept(
+    noexcept(std::forward<Fn>(f)(std::forward<Args>(args)...)))
+{
+    return std::forward<Fn>(f)(std::forward<Args>(args)...);
+}
+
+template<class F, class... Args>
+struct is_invocable {
+    template<typename U, typename Obj, typename... FuncArgs>
+    static auto test(U&& p)
+        -> decltype((std::declval<Obj>().*p)(std::declval<FuncArgs>()...),
+                    void(),
+                    std::true_type());
+    template<typename U, typename... FuncArgs>
+    static auto test(U* p) -> decltype((*p)(std::declval<FuncArgs>()...),
+                                       void(),
+                                       std::true_type());
+    template<typename U, typename... FuncArgs>
+    static auto test(...) -> decltype(std::false_type());
+
+    static constexpr bool value = decltype(test<F, Args...>(0))::value;
+};
+
+}  // namespace func
+}  // namespace lnav
+
+#endif