Compute the numeric operators on NumberSet

phpstan-baseline.neon

@@ -1513,12 +1513,6 @@ parameters:
 			count: 1
 			path: src/Type/OperatorTypeHelper.php
 
-		-
-			rawMessage: PHPDoc tag @var with type float|int|null is not subtype of type int|null.
-			identifier: varTag.type
-			count: 6
-			path: src/Type/OperatorTypeHelper.php
-
 		-
 			rawMessage: Creating new ReflectionClass is a runtime reflection concept that might not work in PHPStan because it uses fully static reflection engine. Use objects retrieved from ReflectionProvider instead.
 			identifier: phpstanApi.runtimeReflection

src/Type/Constant/ConstantFloatType.php

@@ -13,6 +13,7 @@
 use PHPStan\Type\FloatType;
 use PHPStan\Type\GeneralizePrecision;
 use PHPStan\Type\IsSuperTypeOfResult;
+use PHPStan\Type\NumberSet;
 use PHPStan\Type\Traits\ConstantNumericComparisonTypeTrait;
 use PHPStan\Type\Traits\ConstantScalarTypeTrait;
 use PHPStan\Type\Type;
@@ -122,6 +123,15 @@ private function toIntegerValue(): int
 		return is_finite($this->value) ? (int) $this->value : 0;
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		if (is_nan($this->value)) {
+			return new NumberSet([], [], true);
+		}
+
+		return new NumberSet([], [[$this->value, $this->value]], false);
+	}
+
 	public function toInteger(): Type
 	{
 		return new ConstantIntegerType($this->toIntegerValue());

src/Type/Constant/ConstantIntegerType.php

@@ -12,6 +12,7 @@
 use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\IsSuperTypeOfResult;
+use PHPStan\Type\NumberSet;
 use PHPStan\Type\Traits\ConstantNumericComparisonTypeTrait;
 use PHPStan\Type\Traits\ConstantScalarTypeTrait;
 use PHPStan\Type\Type;
@@ -36,6 +37,11 @@ public function __construct(private int $value)
 		parent::__construct();
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		return new NumberSet([[$this->value, $this->value]], [], false);
+	}
+
 	public function getValue(): int
 	{
 		return $this->value;

src/Type/ExponentiateHelper.php

@@ -139,16 +139,19 @@ private static function exponentiateConstantScalar(ConstantScalarType $base, Typ
 	 */
 	private static function getIntegerBounds(Type $type): ?array
 	{
-		if ($type instanceof IntegerRangeType) {
-			return [$type->getMin(), $type->getMax()];
+		$numberSet = $type->toNumberSet();
+		if ($numberSet === null || $numberSet->getFloatIntervals() !== [] || $numberSet->hasNan()) {
+			return null;
 		}
 
-		$values = $type->getConstantScalarValues();
-		if (count($values) === 1 && is_int($values[0])) {
-			return [$values[0], $values[0]];
+		// plain int stays (float|int): the intervals read an open end as no bound
+		// at all, not as PHP_INT_MIN or PHP_INT_MAX, whose powers overflow
+		$intervals = $numberSet->getIntegerIntervals();
+		if ($intervals === [[null, null]] || count($intervals) !== 1) {
+			return null;
 		}
 
-		return null;
+		return $intervals[0];
 	}
 
 	/**

src/Type/FloatRangeType.php

@@ -420,6 +420,11 @@ public function toBoolean(): BooleanType
 		return new BooleanType();
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		return new NumberSet([], [[$this->min, $this->max]], false);
+	}
+
 	public function toInteger(): Type
 	{
 		// casting a float outside of the int range is undefined

src/Type/FloatType.php

@@ -142,6 +142,11 @@ public function toNumber(): Type
 		return $this;
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		return new NumberSet([], [[-INF, INF]], true);
+	}
+
 	public function toBitwiseNotType(): Type
 	{
 		return new IntegerType();

src/Type/IntegerRangeType.php

@@ -181,6 +181,11 @@ public static function createAllGreaterThanOrEqualTo($value): Type
 		return self::fromInterval(is_nan($value) ? 0 : (int) ceil($value), null);
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		return new NumberSet([[$this->min, $this->max]], [], false);
+	}
+
 	public function getMin(): ?int
 	{
 		return $this->min;

src/Type/IntegerType.php

@@ -61,6 +61,11 @@ public function toNumber(): Type
 		return $this;
 	}
 
+	public function toNumberSet(): NumberSet
+	{
+		return new NumberSet([[null, null]], [], false);
+	}
+
 	public function toBitwiseNotType(): Type
 	{
 		return new IntegerType();