toString() for
everything else.
var.toStringRoundTrip
string toStringRoundTrip() const @safeShortest text that parses back to the exact stored floating-point value.
toString is display-oriented and can discard stored digits; this explicit opt-in formats FLOAT, DOUBLE, and REAL (stored as double) with the smallest number of significant digits that round-trips exactly, covering NaN, infinities, signed zero, and extreme exponents. Every other kind delegates to toString unchanged — in particular native arrays keep their documented display policy.
Returns
The round-trip text for floating-point scalars;