Does not build with Boost 1.77 beta1

Build testing the OpenBSD ports tree with Boost 1.77. Kea 1.8.2 does not build with Boost 1.77 beta1 as shown..

c++ -DHAVE_CONFIG_H -I. -I../../.. -I../../../src/lib -I../../../src/lib -DDHCP_DATA_DIR="/var/lib/kea" -DTOP_BUILDDIR="../../.." -DKEA_LFC_EXECUTABLE="/usr/local/sbin/kea-lfc" -isystem /usr/local/include -I/usr/local/include/mysql -I/usr/local/include/mysql/mysql -DOS_BSD -Qunused-arguments -Wall -Wextra -Wnon-virtual-dtor -Wwrite-strings -Woverloaded-virtual -Wno-sign-compare -pthread -Wno-missing-field-initializers -Wno-unused-variable -Wno-unused-parameter -fPIC -O2 -pipe -MT libkea_dhcpsrv_la-timer_mgr.lo -MD -MP -MF .deps/libkea_dhcpsrv_la-timer_mgr.Tpo -c timer_mgr.cc -fPIC -DPIC -o .libs/libkea_dhcpsrv_la-timer_mgr.o
timer_mgr.cc:68:14: error: no template named 'map' in namespace 'std'; did you mean 'max'?
typedef std::map<std::string, TimerInfoPtr> TimerInfoMap;
        ~~~~~^~~
             max
/usr/include/c++/v1/algorithm:2624:1: note: 'max' declared here
max(const _Tp& __a, const _Tp& __b, _Compare __comp)
^
timer_mgr.cc:68:14: error: C++ requires a type specifier for all declarations
typedef std::map<std::string, TimerInfoPtr> TimerInfoMap;
~~~~~~~      ^
timer_mgr.cc:68:14: error: typedef declarator cannot be qualified
typedef std::map<std::string, TimerInfoPtr> TimerInfoMap;
        ~~~~~^
timer_mgr.cc:68:14: error: typedef name must be an identifier
typedef std::map<std::string, TimerInfoPtr> TimerInfoMap;
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
timer_mgr.cc:68:44: error: expected ';' after top level declarator
typedef std::map<std::string, TimerInfoPtr> TimerInfoMap;
                                           ^
                                           ;
timer_mgr.cc:160:5: error: unknown type name 'TimerInfoMap'
    TimerInfoMap registered_timers_;
    ^
timer_mgr.cc:207:5: error: use of undeclared identifier 'TimerInfoMap'
    TimerInfoMap::iterator timer_info_it = registered_timers_.find(timer_name);
    ^
timer_mgr.cc:233:5: error: unknown type name 'TimerInfoMap'
    TimerInfoMap registered_timers_copy(registered_timers_);
    ^
timer_mgr.cc:236:10: error: use of undeclared identifier 'TimerInfoMap'
    for (TimerInfoMap::iterator timer_info_it = registered_timers_copy.begin();
         ^
timer_mgr.cc:256:4: error: use of undeclared identifier 'TimerInfoMap'
   TimerInfoMap::const_iterator timer_info_it = registered_timers_.find(timer_name);
   ^
timer_mgr.cc:275:5: error: use of undeclared identifier 'TimerInfoMap'
    TimerInfoMap::const_iterator timer_info_it = registered_timers_.find(timer_name);
    ^
timer_mgr.cc:287:5: error: use of undeclared identifier 'TimerInfoMap'
    TimerInfoMap::iterator timer_info_it = registered_timers_.find(timer_name);
    ^
timer_mgr.cc:160:18: warning: private field 'registered_timers_' is not used [-Wunused-private-field]
    TimerInfoMap registered_timers_;
                 ^
1 warning and 12 errors generated.