base/callback_unittest.nc

// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This is a "No Compile Test" suite.
// http://dev.chromium.org/developers/testing/no-compile-tests

#include "base/callback.h"

namespace base {

class Parent {
};

class Child : Parent {
};

#if defined(NCTEST_EQUALS_REQUIRES_SAMETYPE)  // [r"fatal error: invalid operands to binary expression \('RepeatingCallback<void \(\)>' and 'RepeatingCallback<int \(\)>'\)"]

// Attempting to call comparison function on two callbacks of different type.
//
// This should be a compile time failure because each callback type should be
// considered distinct.
void WontCompile() {
  RepeatingCallback<void()> c1;
  RepeatingCallback<int()> c2;
  c1 == c2;
}

#elif defined(NCTEST_CONSTRUCTION_FROM_SUBTYPE)  // [r"fatal error: no viable conversion from 'RepeatingCallback<Parent \(\)>' to 'RepeatingCallback<Child \(\)>'"]

// Construction of RepeatingCallback<A> from RepeatingCallback<B> if A is
// supertype of B.
//
// While this is technically safe, most people aren't used to it when coding
// C++ so if this is happening, it is almost certainly an error.
void WontCompile() {
  RepeatingCallback<Parent()> cb_a;
  RepeatingCallback<Child()> cb_b = cb_a;
}

#elif defined(NCTEST_ASSIGNMENT_FROM_SUBTYPE)  // [r"fatal error: no viable overloaded '='"]

// Assignment of RepeatingCallback<A> from RepeatingCallback<B> if A is
// supertype of B. See explanation for NCTEST_CONSTRUCTION_FROM_SUBTYPE.
void WontCompile() {
  RepeatingCallback<Parent()> cb_a;
  RepeatingCallback<Child()> cb_b;
  cb_a = cb_b;
}

#elif defined(NCTEST_ONCE_THEN_MISMATCH)  // [r"static assertion failed due to requirement '.+': \|then\| callback's parameter must be constructible from return type of \|this\|\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `int*` to `float*`.
void WontCompile() {
  OnceCallback<int*()> original;
  OnceCallback<void(float*)> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_ONCE_THEN_MISMATCH_VOID_RESULT)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback cannot accept parameters if \|this\| has a void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `void` to `float`.
void WontCompile() {
  OnceCallback<void()> original;
  OnceCallback<void(float)> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_ONCE_THEN_MISMATCH_VOID_PARAM)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback must accept exactly one parameter if \|this\| has a non-void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `int` to `void`.
void WontCompile() {
  OnceCallback<int()> original;
  OnceCallback<void()> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_REPEATINGRVALUE_THEN_MISMATCH)  // [r"static assertion failed due to requirement '.+': \|then\| callback's parameter must be constructible from return type of \|this\|\."]

// Calling Then() with a callback that can't receive the original
// callback's return type.  Here we would pass `int*` to `float*`.
void WontCompile() {
  RepeatingCallback<int*()> original;
  RepeatingCallback<void(float*)> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_REPEATINGRVALUE_THEN_MISMATCH_VOID_RESULT)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback cannot accept parameters if \|this\| has a void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `void` to `float`.
void WontCompile() {
  RepeatingCallback<void()> original;
  RepeatingCallback<void(float)> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_REPEATINGRVALUE_THEN_MISMATCH_VOID_PARAM)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback must accept exactly one parameter if \|this\| has a non-void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `int` to `void`.
void WontCompile() {
  RepeatingCallback<int()> original;
  RepeatingCallback<void()> then;
  std::move(original).Then(std::move(then));
}

#elif defined(NCTEST_REPEATINGLVALUE_THEN_MISMATCH)  // [r"static assertion failed due to requirement '.+': \|then\| callback's parameter must be constructible from return type of \|this\|\."]

// Calling Then() with a callback that can't receive the original
// callback's return type.  Here we would pass `int*` to `float*`.
void WontCompile() {
  RepeatingCallback<int*()> original;
  RepeatingCallback<void(float*)> then;
  original.Then(then);
}

#elif defined(NCTEST_REPEATINGLVALUE_THEN_MISMATCH_VOID_RESULT)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback cannot accept parameters if \|this\| has a void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `void` to `float`.
void WontCompile() {
  RepeatingCallback<void()> original;
  RepeatingCallback<void(float)> then;
  original.Then(then);
}

#elif defined(NCTEST_REPEATINGLVALUE_THEN_MISMATCH_VOID_PARAM)  // [r"fatal error: static assertion failed due to requirement '.+': \|then\| callback must accept exactly one parameter if \|this\| has a non-void return type\."]

// Calling Then() with a callback that can't receive the original
// callback's return type. Here we would pass `int` to `void`.
void WontCompile() {
  RepeatingCallback<int()> original;
  RepeatingCallback<void()> then;
  original.Then(then);
}

#endif

}  // namespace base