map中括号的坑踩过的坑

【map中括号的坑】这个坑其实我早就知道，只不过是没有这个数据就会自动创建而已，顶多是一些错误数据而已，今天竟然出现了编译错误！！！我特么还以为是构造函数的问题，查了一小时。我平时map用的很少，都是unordered_map，但是如果数据量小，哈希的效率还没有红黑树高，我就换了map，开始的时候看到源码中用的中括号，我就用了，也过了，就没当回事，后来自己大改，编译错误就出现了。
报的这个错误

In instantiation of ‘std::pair<_T1, _T2>::pair(std::tuple<_Args1 ...>&, std::tuple<_Args2 ...>&, std::_Index_tuple<_Indexes1 ...>, std::_Index_tuple<_Indexes2 ...>) [with _Args1 = {const int&}; unsigned int ..._Indexes1 = {0u}; _Args2 = {}; unsigned int ..._Indexes2 = {}; _T1 = const int; _T2 = thread_graphic]’: /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/tuple:1575:63:required from ‘std::pair<_T1, _T2>::pair(std::piecewise_construct_t, std::tuple<_Args1 ...>, std::tuple<_Args2 ...>) [with _Args1 = {const int&}; _Args2 = {}; _T1 = const int; _T2 = thread_graphic]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/ext/new_allocator.h:120:4:required from ‘void __gnu_cxx::new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = std::pair; _Args = {const std::piecewise_construct_t&, std::tuple, std::tuple<>}; _Tp = std::_Rb_tree_node >]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/bits/alloc_traits.h:455:4:required from ‘static void std::allocator_traits<_CharT> >::construct(std::allocator_traits<_CharT> >::allocator_type&, _Up*, _Args&& ...) [with _Up = std::pair; _Args = {const std::piecewise_construct_t&, std::tuple, std::tuple<>}; _Tp = std::_Rb_tree_node >; std::allocator_traits<_CharT> >::allocator_type = std::allocator > >]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/bits/stl_tree.h:543:32:required from ‘void std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_construct_node(std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_Link_type, _Args&& ...) [with _Args = {const std::piecewise_construct_t&, std::tuple, std::tuple<>}; _Key = int; _Val = std::pair; _KeyOfValue = https://www.it610.com/article/std::_Select1st >; _Compare = std::less; _Alloc = std::allocator >; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_Link_type = std::_Rb_tree_node >*]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/bits/stl_tree.h:560:4:required from ‘std::_Rb_tree_node<_Val>* std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_create_node(_Args&& ...) [with _Args = {const std::piecewise_construct_t&, std::tuple, std::tuple<>}; _Key = int; _Val = std::pair; _KeyOfValue = https://www.it610.com/article/std::_Select1st >; _Compare = std::less; _Alloc = std::allocator >; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_Link_type = std::_Rb_tree_node >*]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/bits/stl_tree.h:2196:64:required from ‘std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_emplace_hint_unique(std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator, _Args&& ...) [with _Args = {const std::piecewise_construct_t&, std::tuple, std::tuple<>}; _Key = int; _Val = std::pair; _KeyOfValue = https://www.it610.com/article/std::_Select1st >; _Compare = std::less; _Alloc = std::allocator >; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator = std::_Rb_tree_iterator >; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator = std::_Rb_tree_const_iterator >]’ /opt/hisi-linux/x86-arm/arm-himix200-linux/arm-linux-gnueabi/include/c++/6.3.0/bits/stl_map.h:483:8:required from ‘std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const key_type&) [with _Key = int; _Tp = thread_graphic; _Compare = std::less; _Alloc = std::allocator >; std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type = thread_graphic; std::map<_Key, _Tp, _Compare, _Alloc>::key_type = int]’