Use this reference to select the C++ installation interface or look up a retained CEL signature. Operation links point to the CEL language book, which defines numeric behavior, error conditions, and examples.

Package and installer

The CMake package is cel-std; its exported target is cel::std. The public header is <cel/std.hpp>. Call cel::stdlib::install with a cel::op_lookup before constructing your parser. See the tutorial for a compiled example.

The installer registers persistent ordinary and receiver-call signatures. The receiver supplies the first operand; no numeric conversions are introduced. Independent libraries can register disjoint overloads before or after installation. Install each exact standard-library signature only once per lookup.

Retained CEL signatures

Every f64 maps to C++ double. Scalar result types remain f64, including rounding operations. sin_cos returns a structural tuple whose C++ adapter is std::tuple<double, double>.

The following table is the entire port, not the book's larger Rust type set:

CEL signature	Operation contract
min(a: f64, b: f64) -> f64	min
max(a: f64, b: f64) -> f64	max
clamp(x: f64, lo: f64, hi: f64) -> f64	clamp
abs(x: f64) -> f64	abs
signum(x: f64) -> f64	signum
sqrt(x: f64) -> f64	sqrt
floor(x: f64) -> f64	floor
ceil(x: f64) -> f64	ceil
trunc(x: f64) -> f64	trunc
fract(x: f64) -> f64	fract
round_ties_even(x: f64) -> f64	round_ties_even
round(x: f64) -> f64	round
sin(x: f64) -> f64	sin
cos(x: f64) -> f64	cos
tan(x: f64) -> f64	tan
asin(x: f64) -> f64	asin
acos(x: f64) -> f64	acos
atan(x: f64) -> f64	atan
atan2(y: f64, x: f64) -> f64	atan2
sin_cos(x: f64) -> (f64, f64)	sin_cos
to_radians(x: f64) -> f64	to_radians
to_degrees(x: f64) -> f64	to_degrees
hypot(x: f64, y: f64) -> f64	hypot
cbrt(x: f64) -> f64	cbrt
powf(x: f64, exponent: f64) -> f64	powf
exp(x: f64) -> f64	exp
exp2(x: f64) -> f64	exp2
ln(x: f64) -> f64	ln
log(x: f64, base: f64) -> f64	log
log2(x: f64) -> f64	log2
log10(x: f64) -> f64	log10
recip(x: f64) -> f64	recip
mul_add(x: f64, multiplier: f64, addend: f64) -> f64	mul_add
rem_euclid(x: f64, divisor: f64) -> f64	rem_euclid
copysign(magnitude: f64, sign: f64) -> f64	copysign

No powi, integer, or f32 signature is installed. Those parts of the linked book describe Rust capabilities outside this port.

Floating-point environment

Build for IEEE 754 binary64 without fast-math assumptions. The implementation uses C++ standard-library math and preserves the book's documented NaN, infinity, signed-zero, and rounding behavior. Transcendental results need not be bit-identical across implementations; compare them using a tolerance. NaN payloads and signs are unspecified.

round_ties_even is independent of the ambient rounding mode and does not change that mode. The library does not promise to preserve floating-point exception flags or errno.

During evaluation, invalid clamp bounds throw std::invalid_argument("invalid clamp bounds"). Other numeric domain failures produce the floating-point results documented in the book. Unsupported signatures are parser compilation errors.