typX is a Go package that provides useful types, helpers and utilities. It currently includes the following:

• Nil - Represents a nullable value. Implements SQL, JSON, and BSON encoding. Use instead of *T for nullable fields.
• Opt - Represents an optional (present vs. absent) value. Implements JSON (omitzero) and BSON (omitempty) encoding. Use for optional fields in API payloads.
• Dyn - A dynamic type that holds any value with full support for JSON, SQL, and BSON encoding. Useful for storing arbitrary JSON/BSON data in databases.
• KV / KVs - A generic key-value pair and slice type with full JSON, SQL, and BSON encoding support. Useful for query parameters, metadata, and ordered maps.
• Range / MultiRange - PostgreSQL-compatible range and multirange types for any cmp.Ordered type (e.g. int, float64, string). Support SQL scan/value using native PG range literals.
• OrderedRange / OrderedMultiRange - Range and multirange types for custom types implementing the Ordered[T] interface. When the bound type also implements PGBoundMarshaler / PGBoundUnmarshaler, native PG range literals are used; otherwise values are JSON-encoded.
• Ordered / PGBoundMarshaler / PGBoundUnmarshaler - Interfaces for custom ordered types and PostgreSQL bound serialization.
• DateTime - A time.Time wrapper implementing Ordered[DateTime], PGBoundMarshaler, PGBoundUnmarshaler, sql.Scanner, and driver.Valuer. Ready to use as bounds in OrderedRange[DateTime] / OrderedMultiRange[DateTime] (maps to tstzrange / tstzmultirange).
• Str64 - A []byte type that transparently encodes as unpadded base64url (alphabet: A-Z a-z 0-9 - _) in JSON and any text transport via encoding.TextMarshaler / encoding.TextUnmarshaler. Useful for compact UUID representation, URL-safe tokens, and loggable binary values.
• Must / Must2 / Must3 - Generic panic-on-error helpers for unwrapping one, two, or three return values alongside an error.
• Pointer Helpers - FromPtr and FromPtrOrZero for safe pointer dereferencing. (Ptr is deprecated since Go 1.26 provides value initialization via the built-in new.)

// Main model
type User struct {
    ID             typx.Str64                      // compact base64url representation of raw ID bytes
    Name           string
    Mobile         string
    Landline       typx.Nil[string]                // nullable, instead of *string
    AdditionalInfo typx.Dyn                        // arbitrary JSON/BSON data
    ActiveWindow   typx.OrderedRange[typx.DateTime] // tstzrange column
}

// A sample DTO for PATCH /api/v1/user/{id}
// Fields absent from the request body remain unset (Opt.Set == false).
type UpdateUserDTO struct {
    Name           typx.Opt[string]
    Mobile         typx.Opt[string]
    Landline       typx.Opt[typx.Nil[string]]
    AdditionalInfo typx.Opt[typx.Dyn]
}

// KV / KVs example
func NewDatabaseConnection(config ...typx.KV[string, string]) (*sql.DB, error) {
    for _, kv := range config {
        cfg.Set(kv.Key, kv.Val)
    }
    // ...
}

// Range example (built-in ordered types, e.g. int)
var r typx.Range[int]
_ = r.Scan("[10,20)")         // lower inclusive, upper exclusive
contains := r.Contains(15)   // true

// MultiRange example
var mr typx.MultiRange[int]
_ = mr.Scan("{[1,5],[10,20)}")
contains = mr.Contains(12)   // true

// OrderedRange with DateTime (maps to tstzrange)
var tr typx.OrderedRange[typx.DateTime]
_ = tr.Scan(`["2024-01-01 00:00:00+00","2025-01-01 00:00:00+00")`)

// Str64 — compact URL-safe UUID
uid := uuid.New()
s := typx.Str64(uid[:])      // 16 bytes → 22-char base64url string
fmt.Println(s)               // e.g. "BpLnfgDsc2WD8F2qNkHydQ"
s2, _ := typx.FromString(s.String())
uid2, _ := uuid.FromBytes(s2)

// Must helpers
val := typx.Must(strconv.Atoi("42")) // panics on error