| // Ceres Solver - A fast non-linear least squares minimizer | |
| // Copyright 2026 Google Inc. All rights reserved. | |
| // http://ceres-solver.org/ | |
| // | |
| // Redistribution and use in source and binary forms, with or without | |
| // modification, are permitted provided that the following conditions are met: | |
| // | |
| // * Redistributions of source code must retain the above copyright notice, | |
| // this list of conditions and the following disclaimer. | |
| // * Redistributions in binary form must reproduce the above copyright notice, | |
| // this list of conditions and the following disclaimer in the documentation | |
| // and/or other materials provided with the distribution. | |
| // * Neither the name of Google Inc. nor the names of its contributors may be | |
| // used to endorse or promote products derived from this software without | |
| // specific prior written permission. | |
| // | |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
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| // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
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| // POSSIBILITY OF SUCH DAMAGE. | |
| // | |
| // Author: hellston20a@gmail.com (H S Helson Go) | |
| #ifndef CERES_PUBLIC_CONSTANTS_H_ | |
| #define CERES_PUBLIC_CONSTANTS_H_ | |
| // TODO(HSHelson): This header should no longer be necessary once C++20's | |
| // <numbers> (e.g. std::numbers::pi_v) becomes usable | |
| // The constant is computed using mpmath by the following shell command: | |
| // | |
| // python3 - <<EOF | |
| // from mpmath import mp | |
| // mp.dps = 64 | |
| // print(mp.pi) | |
| // EOF | |
| namespace ceres::constants { | |
| // π | |
| template <typename T> | |
| inline constexpr T pi_v( | |
| 3.141592653589793238462643383279502884197169399375105820974944592L); | |
| inline constexpr double pi = pi_v<double>; | |
| } // namespace ceres::constants | |
| #endif // CERES_PUBLIC_CONSTANTS_H_ |