Timestamp

Data Type	Object	Slice	Vector	Option
Timestamp (`Timestamp` or `flat_message::Timestamp`)	Yes	-	-	-

Remarks:

A Timestamp is a 64-bit value that represents time in milliseconds since the UNIX epoch (January 1, 1970, 00:00:00 UTC) and is intended to appear only once in a struct. The following example will not compile as it uses two fields with the type Timestamp:

#![allow(unused)]
fn main() {
use flat_message::*;

// code will not compile (two timestamps)
#[derive(FlatMessage)]
struct Example {
    created_at: Timestamp,
    updated_at: Timestamp
}
}

The use of Timestamp is optional—you don't need to include it in your structure unless you want to track timing information.
Since Timestamp can be used only once per struct, its field name is not stored; it will be automatically mapped to any field with the same type.
The timestamp value is stored as an unsigned 64-bit integer, providing a range that can represent dates far into the future.
When system time retrieval fails, the timestamp defaults to 0 (representing the UNIX epoch).
The Timestamp type implements common traits like Copy, Clone, Debug, Eq, PartialEq, Ord, and PartialOrd, making it suitable for comparisons and sorting operations.

Methods

The following methods are available for a Timestamp:

Method	Purpose
`with_value(value: u64)`	Creates a new Timestamp instance with a manually provided value in milliseconds since the UNIX epoch. Use this when you have a pre-existing timestamp value.
`now()`	Creates a new Timestamp with the current system time in milliseconds since the UNIX epoch. Returns a timestamp with value 0 if system time cannot be obtained.
`from_system_time(time: SystemTime)`	Creates a new Timestamp from a `std::time::SystemTime` value. Returns a timestamp with value 0 if the conversion fails.
`value(&self)`	Returns the underlying 64-bit integer value of the Timestamp in milliseconds since the UNIX epoch. Useful for storing or transmitting the timestamp value.

Example

#![allow(unused)]
fn main() {
use flat_message::*;

#[derive(FlatMessage)]
struct LogEntry {
    message: String,
    level: u8,
    created_at: Timestamp
}

// Usage examples
let entry = LogEntry {
    message: "Application started".to_string(),
    level: 1,
    created_at: Timestamp::now()
};

// Create with specific timestamp
let historical_entry = LogEntry {
    message: "System boot".to_string(),
    level: 0,
    created_at: Timestamp::with_value(1640995200000) // Jan 1, 2022 00:00:00 UTC
};
}