`std::abs()` doesn't work on custom types. While one can use the 3-argument version of `DistanceFrom()` to specify how to compute the distance, it's not as convenient as defining `abs()` for the custom type once in the type's namespace and then use the 2-argument version.
PiperOrigin-RevId: 735741409
Change-Id: If8fb668455eb963a2ccf089f7467c64965a2e7a6
We have a bunch of matchers for asserting that a value is near the target value, e.g.
`DoubleNear()` and `FloatNear()`. These matchers only work for specific types (`double` and `float`). They are not flexible enough to support other types that have the notion of a "distance" (e.g. N-dimensional points and vectors, which are commonly used in ML).
In this diff, we generalize the idea to a `DistanceFrom(target, get_distance, m)` matcher that works on arbitrary types that have the "distance" concept (the `get_distance` argument is optional and can be omitted for types that support `-`, and `std::abs()`). What it does:
1. compute the distance between the value and the target using `get_distance(value, target)`; if `get_distance` is omitted, compute the distance as `std::abs(value - target)`.
2. match the distance against matcher `m`; if the match succeeds, the `DistanceFrom()` match succeeds.
Examples:
```
// 0.5's distance from 0.6 should be <= 0.2.
EXPECT_THAT(0.5, DistanceFrom(0.6, Le(0.2)));
Vector2D v1(3.0, 4.0), v2(3.2, 6.0);
// v1's distance from v2, as computed by EuclideanDistance(v1, v2),
// should be >= 1.0.
EXPECT_THAT(v1, DistanceFrom(v2, EuclideanDistance, Ge(1.0)));
```
PiperOrigin-RevId: 734593292
Change-Id: Id6bb7074dc4aa4d8abd78b57ad2426637e590de5
Property() should not be used against member functions that you do not own. Make
this warning more prominent in matchers.md and add it to gmock-matchers.h.
PiperOrigin-RevId: 727753777
Change-Id: Idf9155103b04b98efc957ff0d0cf3a8d8662eb72
Add `Conditional` wrapper to gtest
This follows an initial proposal for an 'EqIff` matcher. `Conditional` was considered more precise as an EqIff() matcher may suffer from `Iff` not being universally understood.
PiperOrigin-RevId: 383407665
Implement 'Contains(e).Times(n)' matcher modifier which allows to test for arbitrary occurrences including absence with Times(0).
PiperOrigin-RevId: 382210276
