зарегистрировать глобальное производное имя и определение метрики (register a global derived metric name and definition)
Оценка выражения (Expression evaluation)
For the binary arithmetic operators, if either operand must be
scaled (e.g. convert bytes to Kbytes) then the result is promoted
to PM_TYPE_DOUBLE. Otherwise the type of the result is
determined by the types of the operands, as per the following
table which is evaluated from top to bottom until a match is
found.
┌─────────────────────────┬──────────┬────────────────┐
│ Operand Types │ Operator │ Result Type │
├─────────────────────────┼──────────┼────────────────┤
│either is PM_TYPE_DOUBLE │ any │ PM_TYPE_DOUBLE │
├─────────────────────────┼──────────┼────────────────┤
│any │ division │ PM_TYPE_DOUBLE │
├─────────────────────────┼──────────┼────────────────┤
│either is PM_TYPE_FLOAT │ any │ PM_TYPE_FLOAT │
├─────────────────────────┼──────────┼────────────────┤
│either is PM_TYPE_U64 │ any │ PM_TYPE_U64 │
├─────────────────────────┼──────────┼────────────────┤
│either is PM_TYPE_64 │ any │ PM_TYPE_64 │
├─────────────────────────┼──────────┼────────────────┤
│either is PM_TYPE_U32 │ any │ PM_TYPE_U32 │
├─────────────────────────┼──────────┼────────────────┤
│otherwise (both are │ any │ PM_TYPE_32 │
│PM_TYPE_32) │ │ │
└─────────────────────────┴──────────┴────────────────┘
