Jacques Lucke
aa4882506c
Using `FunctionRef` is better than using `std::function`, templates and c function pointers in some cases. The trade offs are explained in more detail in code documentation. The following are some of the main benefits of using `FunctionRef`: * It is convenient to use with all kinds of callables. * It is cheaper to construct, copy and (possibly) call compared to `std::function`. * Functions taking a `FunctionRef` as parameter don't need to be declared in header files (as is necessary when using templates usually). Differential Revision: https://developer.blender.org/D10476
103 lines
2.0 KiB
C++
103 lines
2.0 KiB
C++
/* Apache License, Version 2.0 */
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#include "BLI_function_ref.hh"
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#include "testing/testing.h"
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namespace blender::tests {
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static int perform_binary_operation(int a, int b, FunctionRef<int(int, int)> operation)
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{
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return operation(a, b);
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}
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TEST(function_ref, StatelessLambda)
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{
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const int result = perform_binary_operation(4, 6, [](int a, int b) { return a - b; });
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EXPECT_EQ(result, -2);
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}
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TEST(function_ref, StatefullLambda)
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{
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const int factor = 10;
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const int result = perform_binary_operation(
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2, 3, [&](int a, int b) { return factor * (a + b); });
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EXPECT_EQ(result, 50);
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}
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static int add_two_numbers(int a, int b)
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{
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return a + b;
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}
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TEST(function_ref, StandaloneFunction)
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{
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const int result = perform_binary_operation(10, 5, add_two_numbers);
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EXPECT_EQ(result, 15);
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}
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TEST(function_ref, ConstantFunction)
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{
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auto f = []() { return 42; };
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FunctionRef<int()> ref = f;
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EXPECT_EQ(ref(), 42);
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}
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TEST(function_ref, MutableStatefullLambda)
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{
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int counter = 0;
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auto f = [&]() mutable { return counter++; };
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FunctionRef<int()> ref = f;
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EXPECT_EQ(ref(), 0);
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EXPECT_EQ(ref(), 1);
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EXPECT_EQ(ref(), 2);
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}
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TEST(function_ref, Null)
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{
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FunctionRef<int()> ref;
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EXPECT_FALSE(ref);
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auto f = []() { return 1; };
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ref = f;
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EXPECT_TRUE(ref);
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ref = {};
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EXPECT_FALSE(ref);
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}
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TEST(function_ref, CopyDoesNotReferenceFunctionRef)
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{
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auto f1 = []() { return 1; };
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auto f2 = []() { return 2; };
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FunctionRef<int()> x = f1;
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FunctionRef<int()> y = x;
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x = f2;
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EXPECT_EQ(y(), 1);
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}
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TEST(function_ref, CopyDoesNotReferenceFunctionRef2)
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{
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auto f = []() { return 1; };
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FunctionRef<int()> x;
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FunctionRef<int()> y = f;
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FunctionRef<int()> z = static_cast<const FunctionRef<int()> &&>(y);
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x = z;
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y = {};
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EXPECT_EQ(x(), 1);
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}
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TEST(function_ref, ReferenceAnotherFunctionRef)
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{
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auto f1 = []() { return 1; };
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auto f2 = []() { return 2; };
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FunctionRef<int()> x = f1;
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auto f3 = [&]() { return x(); };
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FunctionRef<int()> y = f3;
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EXPECT_EQ(y(), 1);
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x = f2;
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EXPECT_EQ(y(), 2);
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}
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} // namespace blender::tests
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