Initial commit of Ceres Solver.
diff --git a/internal/ceres/casts.h b/internal/ceres/casts.h
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// 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
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: keir@google.com (Keir Mierle)
+
+#ifndef CERES_INTERNAL_CASTS_H_
+#define CERES_INTERNAL_CASTS_H_
+
+#include <cassert>
+#include <cstddef> // For NULL.
+
+namespace ceres {
+
+// Identity metafunction.
+template <class T>
+struct identity_ {
+ typedef T type;
+};
+
+// Use implicit_cast as a safe version of static_cast or const_cast
+// for implicit conversions. For example:
+// - Upcasting in a type hierarchy.
+// - Performing arithmetic conversions (int32 to int64, int to double, etc.).
+// - Adding const or volatile qualifiers.
+//
+// In general, implicit_cast can be used to convert this code
+// To to = from;
+// DoSomething(to);
+// to this
+// DoSomething(implicit_cast<To>(from));
+//
+// base::identity_ is used to make a non-deduced context, which
+// forces all callers to explicitly specify the template argument.
+template<typename To>
+inline To implicit_cast(typename identity_<To>::type to) {
+ return to;
+}
+
+// This version of implicit_cast is used when two template arguments
+// are specified. It's obsolete and should not be used.
+template<typename To, typename From>
+inline To implicit_cast(typename identity_<From>::type const &f) {
+ return f;
+}
+
+// When you upcast (that is, cast a pointer from type Foo to type
+// SuperclassOfFoo), it's fine to use implicit_cast<>, since upcasts
+// always succeed. When you downcast (that is, cast a pointer from
+// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
+// how do you know the pointer is really of type SubclassOfFoo? It
+// could be a bare Foo, or of type DifferentSubclassOfFoo. Thus,
+// when you downcast, you should use this macro. In debug mode, we
+// use dynamic_cast<> to double-check the downcast is legal (we die
+// if it's not). In normal mode, we do the efficient static_cast<>
+// instead. Thus, it's important to test in debug mode to make sure
+// the cast is legal!
+// This is the only place in the code we should use dynamic_cast<>.
+// In particular, you SHOULDN'T be using dynamic_cast<> in order to
+// do RTTI (eg code like this:
+// if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
+// if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
+// You should design the code some other way not to need this.
+
+template<typename To, typename From> // use like this: down_cast<T*>(foo);
+inline To down_cast(From* f) { // so we only accept pointers
+ // Ensures that To is a sub-type of From *. This test is here only
+ // for compile-time type checking, and has no overhead in an
+ // optimized build at run-time, as it will be optimized away
+ // completely.
+
+ // TODO(csilvers): This should use COMPILE_ASSERT.
+ if (false) {
+ implicit_cast<From*, To>(NULL);
+ }
+
+ // uses RTTI in dbg and fastbuild. asserts are disabled in opt builds.
+ assert(f == NULL || dynamic_cast<To>(f) != NULL); // NOLINT
+ return static_cast<To>(f);
+}
+
+} // namespace ceres
+
+#endif // CERES_INTERNAL_CASTS_H_
