Feature ideas for the next version

[philip82148]

• Check for bad pointers (including const char *) (like outside of the segmentation)
• std::format
• time_zone
• Package managers
• log_label_func parameter accepts source_location
• C++23 classes
• Manipulator for string length
• Length limit or some settings for auto-identified type names.
• Test for old compilers

Might not do:

• Builder pattern or something for es_value_t?
• make options namespace a class?