CODE_POINT_MAX get_sequence_1 get_sequence_2 get_sequence_3 get_sequence_4 increase_safely is_code_point_valid is_lead_surrogate is_overlong_sequence is_surrogate is_trail is_trail_surrogate LEAD_OFFSET LEAD_SURROGATE_MAX LEAD_SURROGATE_MIN mask16 mask8 sequence_length SURROGATE_OFFSET TRAIL_SURROGATE_MAX TRAIL_SURROGATE_MIN utf_error validate_next validate_next

is_lead_surrogate() template<typename u16 > bool utf8::internal::is_lead_surrogate ( u16  cp ) 这是这个函数的调用关系图: