fix(*): style and clang warnings

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/kernel/level.cpp

@@ -339,7 +339,7 @@ class level_deserializer : public object_deserializer<level> {
     typedef object_deserializer<level> super;
 public:
     level read() {
-        return super::read([&]() {
+        return super::read([&]() -> level {
                 deserializer & d = get_owner();
                 auto k = static_cast<level_kind>(d.read_char());
                 switch (k) {

src/tests/util/exception.cpp

@@ -45,9 +45,8 @@ static void tst4() {
 
 class ex : public exception {
     std::function<char const *()> m_f;
-    ex(std::function<char const *()> const & f):m_f(f) {}
 public:
-    template<typename F> ex(F && f):m_f(f) {}
+    ex(std::function<char const *()> const & f):m_f(f) {}
     virtual exception * clone() const { return new ex(m_f); }
     virtual void rethrow() const { throw *this; }
     virtual char const * what() const noexcept { return m_f(); }

src/util/name_generator.cpp

@@ -5,6 +5,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 */
 #include <limits>
+#include <algorithm>
 #include "util/name_generator.h"
 
 namespace lean {

src/util/rb_tree.h

@@ -6,6 +6,7 @@ Author: Leonardo de Moura
 */
 #pragma once
 #include <utility>
+#include <algorithm>
 #include "util/rc.h"
 #include "util/debug.h"
 #include "util/buffer.h"
@@ -69,9 +70,10 @@ class rb_tree : public CMP {
         if (n.is_shared()) {
             // std::cout << "SHARED\n";
             return node(new node_cell(*n.m_ptr));
-        } else
+        } else {
             return n;
         }
+    }
 
     static node set_black(node && n) {
         if (n.is_black())
@@ -290,7 +292,7 @@ public:
         lean_assert(check_invariant());
     }
 
-    void erase_min(T const & v) {
+    void erase_min() {
         m_root = set_black(erase_min(m_root.steal()));
         lean_assert(check_invariant());
     }