float_sto_set

Summary. Parse a serialized Amount (native or IOU, with or without a leading field header) back into an XFL.

Signature.

int64_t float_sto_set(uint32_t read_ptr, uint32_t read_len);

Parameters.

Name	Type	Description
read_ptr	uint32_t	Pointer to the serialized amount.
read_len	uint32_t	Length of the serialized amount (8 for a bare number, more with a field header / currency / issuer).

Return value. The XFL value of the amount; a zero amount returns the XFL 0. Errors: OUT_OF_BOUNDS (-1) for a bad buffer; NOT_AN_OBJECT (-23) if read_len < 8, or if a field-header prefix is detected but the buffer is too short to contain the amount.

Common failure patterns.

• Passing fewer than 8 bytes → NOT_AN_OBJECT.

Caveats / notes.

• When read_len > 8, the function inspects the leading byte(s) to skip an sfXxx field header (1, 2, or 3 bytes depending on whether the field/type codes are < 16), then reads the 8-byte amount — so you can pass either a bare 8-byte number or a headered field.
• The currency/issuer of an IOU amount are ignored: only the numeric value is returned.
• Round-trips with float_sto.

Minimal example.

int64_t xfl = float_sto_set((uint32_t)amount_buf, amount_len);

Practical example.

// After float_sto wrote a 49-byte sfAmount into buf, read it straight back:
int64_t xfl = float_sto_set(buf, 49);   // == the original XFL
// A short (8-byte) serialized number round-trips too:
ASSERT(float_sto_set(buf, 9) == 0);     // a serialized zero

Related APIs. float_sto, slot_float.