-text-stroke-width: 0px;"><span style="font-family: 'DejaVu Sans', arial, sans-serif;">the constructor used to construct the object (either implicit or explicit) must satisfy the requirements of </span><code style="font-family: 'DejaVu Sans Mono', courier, monospace !important; background-color: transparent;">constexpr</code><span style="font-family: 'DejaVu Sans', arial, sans-serif;"> constructor. In the case of explicit constructor, it must have <span style="background-color: rgba(0, 0, 0, 0.027451); b